Depends on your definition of "easy"

https://guides.frame.work/Guide/Battery+Replacement+Guide/85

It's past my personal definition, but just barely, since it involves dealing with a ribbon cable and an apparently fragile connection for the battery itself. It's not too bad, but not something I want to try and walk someone through if they're not used to this sort of thing.

Yes, the Framework laptop's battery is more easily replaceable than the new MBP's, from what I can tell without yet having seen iFixit's full teardown of the latter—there's no need to remove the trackpad or deal with adhesives on the Framework, in contrast to the new MBP.

(I'm still thrilled to see this improvement to serviceability on the new MBP, even if previous generations set a low bar.)