Thanks for the report. I both confirmed the issue and agree this would be an improvement. We might relabel this as a bug instead of enhancement, and change its title, if @plone/volto-team and @plone/volto-accessibility Teams agree.

To reproduce, click the circled + icon (Add block button) to get the popup mentioned.

TBH, I think this is a feature. There is even a more straightforward way, which is press the enter key, as you would do in any editor.

Yes, but if you are a mouser or tapper or otherwise tend to use the + to add any block (except Text of course), then it's annoying that a Text block appears as an option in the popup menu, but when you select it, nothing happens. To me that's a bug. This should be changed to either insert a Text block, or remove Text block from the menu options.

In any case, whether it's a bug or feature, is this something worth working on and would be accepted into core?

I agree with @stevepiercy. If we are allowing users to create a new text block when the current block is empty by pressing the Enter key, it would be good to provide the same functionality through the dropdown menu.

I’ll be raising a PR to address this issue shortly.