In reply to Steve Grant.

Thank you for taking the time to share this.

For the first case, I think it's totally valid to consider a server-rendered block for the "hello USERNAME", depending on whether you want to allow customizations or not. You could register a dynamic block, written in PHP, for which you shouldn't need to setup a complex JS environment. I agree and sympathize simple units like this should not require overwhelming setups. I think ACF is doing some cool stuff there. One thing I'm curious about seeing explored is a way to allow you to write a block like the above directly in an HTML block, using tokens for displaying the username, etc, which can be extended server-side as needed.

The menu editor disappearing sounds like an unfortunate hiccup (though frustrating) as things were being put in place. The navigation menu block is meant to be accessed through a site editor but also directly as a standalone thing like before.

The end goal is for things to be simpler yet more expressive. (And for the overall developer experience to be clear and joyful!) There's a lot of the previous toolset that doesn't need to be discarded, and can be mixed with a more interactive template editing experience. The way to build themes evolved through many years, so it's for sure in a more established ground. I appreciate the sincere feedback since the same sense of reassurance needs to be reached. I hope progress happens faster there in the coming weeks.