This will be an ongoing issue for me, so I wanted to repost my thoughts from the original Articulated Thoughts forum here:
I actively dislike D&D's rules. The character customization is great, but the combat is excruciating. I find it low-stakes and far too slow.
Much to my players' vexation, I've made it my personal quest to find a rulebook I actually like. I want a rules-lite system with quick combat and extensive character customization. I'm basically looking for a unicorn. It's easy to find two of the three, but all three is impossible.
OSR systems like Shadowdark are rules-lite and have quick, high-stakes combat. The characters aren't customizable, though. Pathfinder has excellent character customization (maybe the best?), but the rulebook is absurdly long, and combat is a slog.
I wound up running Worlds Without Number a few months ago, and that's as close as I've come. It's kind of an amalgam of heroic and realistic combat systems. The rules are reasonable, character customization is fairly extensive, and combat was fast.
I'm planning to run 13th Age in an upcoming one-shot. I'm going to run that or WWN in my next campaign.
I'd agree with these criticisms of D&D as a system. And I think it goes back to what I said in the previous forum about D&D trying to be something enticing to new players all the time, but also refusing to let go of its past because it doesn't want to alienate those of us that were playing in 3rd Edition, 2nd Edition, and even before that. So it has all these weird vestigial elements that are just the tabletop equivalent of junk-code which actively make the game more obtuse, more difficult to master, and less fun to play.
D&D remains at the top only because of marketing. It's managed to become the brand name of tabletop gaming. But unless what you want is to play D&D itself, there's almost certainly a completely different game out there that better accomplishes what any individual gamer actually wants out of a game.
Even Pathfinder, I would argue, actually does 'just regular D&D' better than D&D does. And I find the argument about Pathfinder being too crunchy to be kind of misleading, because I feel like D&D is just as crunchy in most ways -- but also just less transparent about it. When you sit down with the books, Pathfinder (to me) is easier to follow and, in fact, easier to adjust and tweak, because its systems are laid open to the GM. That's my take, at least.
And D&D is a fun game in most respects. I don't mean to shit on it. But it's just the worst version of itself that it can be. When something is a better you than you, something's been lost and a refocusing is warranted.
I've said it before but I am really curious how Matt Colville's Draw Steel turns out. It -sounds- like it's going to deal with a lot of the D&Disms people don't like, such as convoluted ability trees and sloggy combat. BUT, the impression I get is that it's not going to be as customizable as D&D or Pathfinder in the interests of avoiding the pitfall of having so many combat options that you can't possibly balance it all properly and it becomes a nightmare to keep track of. Can't wait to read it, even if I don't get to play it.
Maybe that's why 'great customization' and 'rules-lite' is such a unicorn. They're almost base-level incompatible ideas. Either the customization has to be all in your flavour text, or you need to expand your crunch for every new bit of customization. I'm not really sure what the solution there is - especially if you want a traditional fantasy game, which will naturally have tons more inherent customization options than something like a historical game.