Why can’t we make high quality decentralized games? 

I’ve seen on YouTube dudes making crazy stuff by themselves with Unreal Engine. 

Is it an architecture thing? Or gameplay design?

Insanely complex stuff in the backend

... also making high-quality stuff is hard on its own.

Most gamedevs don't want to touch crypto at all. 99% of people think this industry is a scam, so hard to attract good talent. So if 1% of gamedevs can make high-quality stuff, only 1% of 1% those are working in crypto :D

I think we can

For example, forgotten playland is very high quality (though not AAA).

But there are not enough players because of marketing problems.

it's probably a bit of both, developing decentralized games has unique challenges

Maybe it's the complexity of integrating decentralized tech with traditional game development. Or perhaps it's the challenge of creating engaging gameplay that truly takes advantage of decentralization.