It all started with neomorphic design, the first time I saw it I liked it a lot(and like you, I was tired of flat design), but alone it does still has its flatness, so I figured out that action elements and inputs can become the less flat elements of this design, so there you have it, neomorphism everywhere :)

There are 2 main drawbacks, the first is about space, which neomorphic design requires to achieve its effect of deepness the second is about layering, the more UI layers you stack up the less the deepness effect is achieved(kind of good I guess because it does force you think of a simple UI/UX)

I think I'll write a blog post about it soon on my blog at blog.thepra.dev