I know it's not a proper metric to judge by, but Tenacity is 10k commits behind Audacity. That's quite a lot to get behind since the split. I'd be interested if Tenacity is actively developed or pretty much just maintaining the software from where they split.
If for your use case v3 or equivalent is essentially feature complete, just getting bug fixes is plenty sufficient.
If they don't have to re-code half the app (new UI kit, not required features, etc.) then what does it matter if they are 10k unrelated commits behind?
I like it's there as a choice for us who prefer the old-timey Audacity for some quick sample editing.