OK I talked to evernote support. Basically because I have a teams account, and I am not an admin for my workplace account, I can create tags but I can't edit them.
So essentially although Teams provides lots of nice functionality, tags are utterly useless in teams. Not being able to edit them, rename then, nest them, delete them, makes them a non-feature.
It's hard to understand the logic of this. In my free account I can do all these things.
As a side note, I left EN a few months ago after years and years of usage because I was just tired of the product. It's this kind of nonsense that reminds me why I left. EN could be so great, but they always seem to trip up at the finish line and do something dumb.
Sigh..