Before Gutenberg, I always said that there was no Dev WordPress, but PHP Dev specialized in WP. The block editor came, and that remains (more or less) true.
Before the block editor was a thing, the truth is that WP development at various agencies was largely snippet-oriented: if someone wanted something, they could just copy and paste some code into functions.php and voilà. The block edit puts a huge obstacle in this process: you have to understand what you are doing.
Putting it another way, the block editor has gone up a notch: now it’s not enough just to have access to a text editor; you need to study JavaScript, React, and the process of deploying these things. It’s new to a lot of people, but it’s basic web programming these days. For someone who just copied and pasted, it’s from another world.
The intent of WordPress has always been to give people a website without the need for a developer. The block editor just created an abyss between those who don’t want to develop anything at all and those who need to create something new.
Good or bad, this change has no turning back. If you are a developer and still don’t work with the block editor, don’t be afraid. It’s easier than it looks.
Part of the problem is the market that hire people to do one thing(WordPress) and forgot that WordPress has several key skills behind it. Some professionals spend years doing “WordPress” but never develop coding skills. But this is not only for WordPress, now there is a big generation of React developers, that doesn’t know HTML or JavaScript.