I started playing Magic: The Gathering pretty much as soon as it came out. A friend who lived down the hall in the dorm brought it back after Thanksgiving break 1993, and within a week or two a bunch of us on 3-North of Moore Hall had decks of our own. My first starter deck was, IIRC, Limited Edition (beta).
Every week, I had budgeted a certain amount of my paycheck for comic books, but if there weren't that many titles I wanted to pick up in a certain week, the remainder usually went into MtG boosters. Later, after moving to Japan and finally earning more than enough to live paycheck to paycheck, I started buying MtG cards again, and occasionally playing. I ended up with a pretty massive collection of cards, which I still have but don't play very often.
Back in the earliest days of the game, part of the charm was seeing what weird and strange cards you'd get in a pack, or what cards your opponents might bring out. We were so far from optimizing our decks. We'd just throw every card we had into them, decks with all five colors and 100-200 cards. The randomness of playing that way was part of the fun and challenge. Of course, over time, as we got more familiar with the game, the novelty factor would wear off...until the next expansion set would come out.
Later, though, and as access to the internet became more common, it became pretty easy to know what all the cards were in a particular set, if you cared to look them up. After I moved from one prefecture to another, the MtG scene was different in my new location. In Toyama, we'd played much the same as my friends back in college. In Yamanashi (circa 2001), the foreign players played with the local Japanese fans, and they were VERY focused on tournament play. I'd met a few Japanese players in Toyama, but didn't really get deeply involved with them. Looking back, it was also probably because they were very heavily tournament focused. Also, one guy who wanted me to trade a rare card for some other rare card of his that I didn't really want, but then got upset when I wouldn't trade...and everyone else seemed to think that I was the asshole because I didn't want to give up a good card for one that I wasn't interested in. ???
Back on topic: pretty much everyone but me in Yamanashi (that I knew of) who played MtG was interested in deck optimization. They'd clone decks of tournament winners. One guy went so far as to tape pieces of paper with the names of cards he didn't own over land cards to turn them into those cards (which I found VERY cheesy) so he could play the "winning deck." That guy nearly blew a gasket when I played a chicken card from the comical Unglued expansion on him. Those silly cards weren't tournament legal! Another friend said I was "screwed" when I bought a deck from the Romance of the Three Kingdoms expansion (which was an Asia only thing IIRC) because they were labeled as part of their beginner series (forget what they called them **just looked it up, Portal**) and again not tournament legal. Shit, I didn't care. I've got Liu Bei and Guan Yu in my Magic deck. And chickens. Screw it. I was having fun.
Needless to say, after a while I gave up on Magic. Especially after they did the whole "Volrath Saga" thing and were trying to tell stories with the expansion sets (to sell more of the shitty novels?) instead of presenting new worlds like in earlier expansions. I guess they went back to the world themes later, but WotC had already lost me as a customer. It had stopped being fun.
I had also long stopped caring about trying to familiarize myself with all the cards in every expansion that came out. And when they made major rules changes (7th edition I think), I was out.
I still have all those cards in my closet, though. And I've even used them from time to time for English teaching.
Anyway, I preface this post with that, because my knowledge of the game is almost 20 years out of date. So take what I have to say about MtG from that perspective. No idea about rules changes or expansions after 6th or 7th edition.
So, what's all this to do with 5E, other than WotC being the producer of both games? Well, as I mentioned in a comment about 5E over at BX Blackrazor, I see the character creation system of 5E to be a lot like the deck building mini-game of MtG.
You've got a base set of rules in MtG. But certain cards (and a larger and larger percentage of the cards as time went on) had ways to bend, twist, or even break the normal rules. And the challenge was not just playing the right cards at the right time, it was having the right combinations of cards in your decks. Brilliant marketing. To have the right cards, players need to spend more money to buy more cards... Until they just start taping bits of note paper over their worthless land cards to turn them into the rare cards. Looking back now, I don't fault the guy so much for doing that.
Anyway, 5E character creation is a lot like the deck building aspect of MtG. You have a book with the basic rules. Then you have races, classes, backgrounds, equipment, spells, and eventually magic items that you can use to "build your deck" and decide what sorts of special abilities you want your PC to have. There's a fun intellectual puzzle solving aspect of it that I quite enjoy.
3E and Pathfinder are also like this, but since everything is more fiddly in those games, it bogs down. 5E does hit a good sweet spot of not being too complex. 3E and Pathfinder are a bit more like a big box of LEGOs. If you follow the instruction booklet (online optimization boards) you come out with the Hogwarts Castle or a TIE Fighter made of LEGO. Go it on your own, it will probably be a bit of a mess and not quite like what you were planning. This is a big part of why I have no desire to go back and replay these games.
Now, as a player, that puzzle-solving aspect of building a character is fun and challenging. But I'm only dealing with my character. It's not that hard to keep all my rules-bending Magic cards of special abilities in order. But as a DM? You've got to be well aware of EVERYONE's special rule bending abilities. Every player, every monster (and there aren't a whole lot of 1/1 no special ability Mon's Goblin Raiders among 5E monsters), every magic item, every NPC. And then they start adding in splatbooks.
For me, trying to run 5E was like the latter days of my MtG play experience. There were games I was in against players with newer expansions where pretty much every card they played, I had to ask them to hand it over so I could read it, since I was unfamiliar with them. I felt that way a lot DMing 5E, and I kept my game limited to the PHB only!
So, when Alexis asked me in the comments of JB's post (link above) why I quit 5E when I said I had fun with it, it's because I STILL have fun with it as a player. If someone else wants to run it, great. I'll play. But I don't have fun if I'm the DM. And that's why I quit it.