first I thought you'd go into the nuance of gpl2 vs 3 or lgpl vs gpl vs agpl? patents, tivoization, cloud use?

:-)

I agree, I didn't make any statement what you can do with the software as long as you are licensed to use it

you are allowed to build atomic bombs, nuclear power plants, tanks, whatever.

but only as long as you comply i.e. give your downstream the freedom you've received.

if you fail at that, you're no longer allowed to use the software for anything.

see section 8 Termination for details

https://www.gnu.org/licenses/gpl-3.0.html#license-text