World of Darkness is a good example. It had a couple robust release schedules that led to two versions, one being a major reboot, and is now no longer a major force in RPGs. They basically released themselves into irrelevance.
That's an interesting, completely unsupportable claim.
FATE is another good example. There's a lot of official content on DriveThru, but most of that is campaign settings and worlds. There's only a single real accessory, and that's pretty much the DMG.
Now you are moving the goal posts, claiming that all those settings aren't actually support for the game, which seems a very strange assertion to make.
Other systems are equally sparse. 13th Age has a couple accessories beyond the core book and bestiary after 18 months. Numenera has a similar amount of content after a comparable length of time.
13th Age does seem to have a sparse support library but then it is not a game with a big footprint. Do you know anyone who actually plays it? I don't. Numenera on the other hand has over 30 accessories available for it of varying sizes, plus a compatible spin off game.
The only game approaching D&D and Pathfinder...
Here's the thing: when we are talking about robust release schedules we are primarily comparing D&D to the likes of Pathfinder. No other games really matter at the scale we are talking about. (Star Wars and Shadowrun are probably the next their down.) there is no reason that D&D 5E could not support a schedule equivalent to PF. Just bringing back Dragon and Dungeon would get them halfway there. Throw in a campaign setting hardback and a few smaller setting expansion and you're there. There is nothing like that level of support on the schedule, and given the size of the D&D team, there won't be. That the new edition of D&D in its launch year has support on par with an indie game like FATE is mind boggling and very revealing on how WotC or Hasbro feel about the property.