Wow, thanks for the tip. I would never in a million years have discovered this otherwise. I don't know if Apple's UX design has gone downhill lately or if I'm just getting older and stupider.

A good idea would be “discovery mode” where buttons appear everywhere which explain what can be done if you don’t want the floating buttons around.

In Settings -> Accessibility -> Display & Text Size you have an option "Button Shapes" that will show a button outline on any clickable text.

I always enable this when setting up an iPhone for a parent (or myself).

One of the least-discoverable features in the phone. One of many such features, sadly.

..thank you so much