If your keys get compromised then you would need new keys in any case.

I think that the sort of people that use PGP are more interested in not having any messages compromised, ever, while still retaining access to their old messages in a secure way. Contrast that with, say, Signal where a forensic tool like Cellebrite will allow access to retained Signal messages[1]. Sure, most of that is due to the inherent insecurity of encrypted instant messaging over, say, encrypted email, but the users in the end don't care. They just want to be able to communicate privately.

[1] https://web.archive.org/web/20201210150311/https://www.celle...