I would (and have) argue that the hobby hasn't actually become all that diverse at all, and that it's currently in a rather big rut that, IMO, is rooted in the obsession with modularity and self-contained design.
That is evidenced by my visiting of TTRPG design spaces and finding a lot of very close-minded and conservative (not in the political sense) attitudes, even amongst the ostensible authorities on the subject.
I recently perused a book called Design Patterns of Successful RPGs, and in it they state very plainly that attempting to resolve a given design problem in a way different from whats already succeeded is bad, essentially saying that innovation in of itself is bad.
And this is a book that Ive seen a number of groups and spaces hold up as a proverbial Bible.
But ultimately, looking beyond those admittedly hobbyist spaces, I still find the hobby rather lacking.
In the past year Ive read through probably close to 300ish TTRPGs, and actively played (to the extent I could either by myself or with some interested friends) about 10% of them, and Ive actually tried out different procedures and mechanics from most of them just to get a sense of how they work.
And what Ive found is that there is a lot of sameyness in these games, with the worst offenders being so plainly derivative that they could have had the same value as one page supplements to whatever they copied.
But between both of these problems, I ended up having to start diving into video game design spaces to really get the kind of info I needed to keep pursuing my game.
And it has in fact worked; Ive learned quite a lot thats smoothed out the things Im developing, and helped me to better define not just my design philosophy but also an answer to that overhyped question of what the game is about, and has helped to instill confidence in the ideas that I was intuiting, as Im able to trace my ideas to design practices that have been proven and actually work without gatekeeping innovation.
I for instance, don't think its a coincidence that I ended up reinventing Tears of the Kingdom's take on Fusion in Durability mechanics when I sat and thought my way through how to best resolve the drawbacks of the idea while maintaining its upsides.
I personally arrived there by breaking down the idea and stripping away its aesthetics, which lead to me treating the idea as a question of how to best make whats essentially an HP bar feel more interesting to have be lowered.
This in turn lead me to realize that I had already solved the problem when I looked at my games normal HP mechanics, and looked at how I sought to resolve the issue of yo-yo healing, ie, preventing people from ignoring healing until you're already dead. In that system, I tied HP (and the other Energies) to Saving Throw mechanics, and whether you're making a Save or making someone else make one, your HP influences the chances of success.
But, for Durability, that solution doesn't go quite far enough, as there wasn't an equivalent to the saving throw mechanics. I did have an equivalent already incentivizing keeping the value up (Weapons/Armor losing strength), but there was nothing that makes restoring those develop more interesting choices, unlike Saving Throws which open up to endless choices.
So, that eventually lead to me figuring that I could leverage the crafting system I was already developing to also foster an interesting Repair system, that made losing Durability an opportunity to make more positive choices rather than a just a punishment for playing, your penance to trudge through rote minutia.
Instead, by introducing different materials into your Repairs, you can diversify what your Equipment can do, allowing not just for more mechanical flexibility but more expressive qualities; even if the player finds themselves in a situation where what they have to repair with isn't ideal, the aesthetics that arise out of using the less ideal is desirable, and with careful balance this will never be something that punishes the player, and at worst will simply not reward them.
This whole idea incidentally was also something I had already intuited by another road, as I had inadvertently already created the underlying system when I codified how my magic systen works. Corruptions are essentially magical Durability, and critical for balancing out the high octane nature of my systems Magic, and Mage classes are able to take them and convert them into a wider array of interesting choices, turning the system from punishment fir playing to opportunity generation to play more.
And lo and behold just as I started bringing my thoughts together on this someone gifted me Breath of the Wild and Tears and there I was cussing up a storm the moment I realized my idea was sitting there, fully realized and successful.
I might never have gotten to that point if I was willing to defer to the conventional "wisdom" of TTRPG design that innovation = bad.