As a designer/developer I've embraced Gutenberg and use it for all my new projects. I've already found Gutenberg to be quite limiting when it comes to creating unique and compelling designs. A lot of my design focus has switched to the themes header/footer layouts.

With the introduction of FSE I feel like those limitations are only going to be increased. Maybe I don't fully understand it yet, but I'm not even sure how I'm supposed to create a standard menu on desktop, which then switches to a 'hamburger' toggle with a popout/overlay animation on mobile.

I hope I'm proven wrong.