Look into ACF Blocks (it's part of ACF now), they allow you to very easily extend Gutenberg with minimal coding and simple templating.

WordPress core team is still working on the "full site editing" project (that is, being able to edit headers, footers and sidebars in Gutenberg). It's coming probably later this year or beginning of 2021. But you can still edit a lot of things with Gutenberg as-is.

https://www.advancedcustomfields.com/resources/blocks/

Gridsome is the one that I use (VueJS version of Gatsby). What are the sorts of things you found it couldn't do?

I want to get our team using it for simpler projects, and I haven't really hit any blockers with Gridsome, whereas I've hit plenty with Wordpress when we need a specific url structure.

It's not that it can't do anything, it's that you have to actually implement things at a lower level. I mean, Gatsby doesn't have any backend CMS out of the box so that's the most obvious thing. If you want to use Gatsby for clients who want to be able to manage their content, you have to select and integrate one.

But even for me, who doesn't need a backend GUI stuff like a contact form was a pain. Luckily I host with Netlify and they have an easy form solution but imagine that across many other situations even for a somewhat simple site. Now you're having to set up accounts with all these other services when before it was all contained in one place. All for what? The benefit doesn't seem substantial enough to me to give all of that up.

Even if you use WordPress as the backend, you've still got to deal with integrating it's API which is more work than something generating all the markup you need etc...

Until recently had been a while since I've done anything wordpress either, but rather than ACF I've always been a fan of https://jeremyhixon.com/tool/wordpress-meta-box-generator/ -- such a neat way to do it for clients. Worked fine with Gutenberg as well.

Use something like Contentful with Gutenberg

I'll look into that, thanks. I need to design the technical solution I am going to use for client work and I want it to be as cutting edge as possible without being a nightmare to maintain.

Putting in a word for Sanity CMS, it's like contentful but more programmatic. It also doesn't need so much of the constant 'publish draft' button clicking.