The whole point of WordPress is that you don't need to do much coding, so that point is moot. The vast majority of WordPress developers are designers or non-technical people who either don't know how to code, or who can hack a bit of code now and then.
When I make a site for a client I have to balance many options 1) how fast can I do it 2) including how many bits and bobs do I have to add in to even make it work 3) What it will look like 4) will the client be able to update it afterwards. Speed and underlying tech is way down the list.
I generally use Enfold [1] to build client sites. Divi's interface is too complex and slow to navigate. VC is faster, and I have used it on occasion. Gutenberg also has a slow interface. Gutenberg also requires the download of loads of blocks or block packages, which surely bloat the page, and cause confusion. I've tried Atomic blocks [2] etc, which only works well when you pair it with the Atomic Blocks theme. But sometimes I might need a different blocks. So now, you've now got multiple hero sections, each with different parameters, css and coding. That's bloat and inconsistency.
Gutenberg simply doesn't give designers the level of control over existing page builders. Read this comparison of Gutenberg vs Elementor [3]. I don't use Elementor, but the author concludes -- like me -- that Gutenberg is no match for exiting page builders. To paraphrase, he concludes that Gutenberg is for unsophisticated users who are creating single page layouts with low precision.
BTW, I don't know what themes or clients you have, but Enfold allows all the elements to be locked so that the clients can't mess with the layout. It's also very easy for them to login and see the page structure so that they know where they are. I'm not saying it's perfect, but it's far better than Gutenberg.
IMHO, instead of finding out what developers actually wanted and were using, WordPress decided to roll its own system, which would be fine if it was optional. But, now that it's core, it's just an inferior, anti-competitive PITA.
[1]https://themeforest.net/item/enfold-responsive-multipurpose-...
[2]https://wordpress.org/plugins/atomic-blocks/
[3]https://createandcode.com/gutenberg-vs-elementor-comparison/