Tooltips

In comparison to v2, v3 uses way more icons and fewer text labels.

That is fine, as long as it is still clear to the user what each button does. That can be achieved with (nicely designed, of course :P) tooltips.

I’ve seen many users who had issues navigating and using v3 due to the lack of tooltips.

v2 also uses tooltips/hover flyouts for displaying additional information. v3 could and should copy that behaviour as well, to once again pack information more densely, while still being compatible with the new look.