rules that just don't seem that innovative
As compared to what, though?
Conceptually, sure, if we wanna get fancy, all the ideas they're explaining have been tried out before in various forms, by various TT RPGs (especially 4E), most of those deeply obscure indies which 90% of people backing this won't even have heard of. But D&D is 100% manufactured from recycled ideas and that's mega-popular, so not sure novelty of individual rules per se matters that much.
But this is the first time I've seen all the rules in the same place, and they're bent towards a very different end to what they typically - in indies which use rules like this, it's rarely in the service of combat, glorious battle, or at least not openly.
I will say obviously there are real similarities to Lancer, but that derives from them having very similar goals, but Lancer has a very specific setting, and one, which whilst extremely cool, has a significant narrower appeal. Also, frankly, even from what we've seen, Lancer is about 1/10th as good at explaining and presenting rules, classes, etc. than MCDM is. I don't think that's just high production values - though they are high - it's also just good writing and real fervour to get people to understand.
(Icon also has some similarities, but is worse-presented than Lancer, despite truly beautiful art, it takes genuine effort to unravel how the game works from the free PDFs.)
They have obviously done an amazing job at establishing an audience who trusts them!
I think a lot of people backing this aren't the audience. I know I'm not.
I don't watch his streams, and I find Matt to be a bit, well, over the top and kind of excessively Gen X in stuff he does. But like, the design here? That's what I want. That's what I've been waiting for.
I think that's what's really going on here. Very games have dared to say "What if combat was actually fun?". 5E kinda sidles up to the idea, but it's desperately afraid of scaring the horses, and refuses to engage with any really fun approach to combat, instead of going with a nicely accessible one. Most indie TT RPGs, even large/expensive ones have, I dunno how to put this super-politely, but a slightly snobby attitude to combat, like, you shouldn't be enjoying this you hogs, you slavering hounds. Violence is a bad thing bad people do and it's not big or cool even though we both kinda know it totally is in an RPG context. That's not a new attitude either - you can go back to say, Cyberpunk 2020 in the 1990s, and read Listen Up, You Primitive Screwheads! and it's very clearly Mike Pondsmith's public-facing attitude, despite him being quite conflicted on the issue.
MCDM is quite clearly devoted to combat being awesome, being tactical, being fun, and the sort of faux-simulation 5E and many OSR games flirt with can burn in its golden hell (and Ninja Scroll is indeed the sort of thing that works better with these kind of rules than 5E-style rules).
TLDR: It's doing what Lancer did, but it's doing it better and with a vastly more mainstream genre - heroic high fantasy.