The biggest problems will be
1: anyone in a commercial environment is generally too busy to spend the required time to raise issues.
2: people who have the time are generally in non-commercial or academic positions.

That’s a recipe for selection bias.

I can say this because modern WP has lots of broken functionality which is vital in a commercial setting, but merely uninteresting to those coding for plaudits.
I raised an issue today that YouTube embedding was broken in the case of using a certain filter and was directed to an issue open for a year with the typical cooling and death of the issue.

My point being: when this filter was altered in WP 5.8 (embed dependency kills youtube embed) a bunch of sites started to fail, no YouTube video would embed. The Gutenberg devs could not care less about that. It’s not shiny enough, it’s not JS so it’s dull.

Is there a fix in JS ?No, there’s a workaround. So why does the PHP filter even exist? It’s broken and seemingly abandoned, untested, reported and ignored – yet it was introduced in WP 5.6 , updated in 5.8 .. and left broken

This is the reason that extending for page-builders will continue to prosper over FSE in a commercial environment because I am absolutely sure that if I build for FSE then the Gutenberg team will deprecate something a month later and I’ll be fending off annoyed clients and fixing sites again.

The team are nice people, lovely people but they have a narrow view. They are designing FSE for small personal blogs occasionally tinkered with by IT academics.

Sometimes I go and visit the home page of the people who say “Closed issue” on GIThub. Hoping to see evidence of a prior life delivering property websites, or a hellish time in an agency, or a big project from a conglomerate. But no, it’s always a perky 2 page blog running the latest WP official theme “welcome to my blog, I hope to update it soon – August 2018”, link to GH, university, & socials.

Again, I’m not saying the core/gutenberg devs are “bad”, because quite the opposite Many of them seem absolutely lovely people, but there seems no concept of what commercial website developers need. I mean, there seems an active disinterest or distaste for commercial site development.

And that will be the problem with FSE engagement
Selection Bias.