Definitely not trivial, you’d have to crawl every single post and every comment to build up profile data on a person. That’s significantly more effort then just pulling an entire post history from a single API call from a user. You’d also be bound to miss data. But I also think posts should have the option to expire, like auto delete this comment or thread after X amount of time, with the option of leaving things be permanent. Who is it really benefiting by making posts stay indefinitely? Mastodon has that feature and it’d be nice to see on Lemmy.