Thanks for your answer! Unfortunately, bouncing simply creates a new audio file for the comp; it doesn't remove the takes, collapse the take layers, or delete the audio files from the pool. To fully clean up a finalized comp, you have to manually delete all the takes individually (right-click + Delete for every take), then manually delete all the layers individually (right-click + Remove Layer for every layer), then go into the pool and manually delete the audio files there. It's a little ... nuts. We're talking 3-ish clicks per take in the comp. So, for a 10-take comp, something like 30 clicks vs. one-to-two clicks in other DAWs. (Clearly, you're supposed to just collapse the layers and forget about all the extra takes.)
There doesn't seem to be much interest in my suggestion (which is fair--I like that the feature requests are democratized here), but I've confirmed this feature exists in the all the other DAWs I've tried (Logic, Reaper, Cubase, and Waveform), so I know I'm not completely crazy! :)