Yeah, I think it can be great if you're intentional about what you're preserving and why. To elaborate a bit, I went from having tens of thousands of emails a few years ago to "only" having about 5k now. I did that by adopting a strategy of aggressively deleting trivial emails. I apply "aggressive decluttering" throughout my digital life, with screenshots also (trying to stay on topic a bit), old conversations, failed creative projects, etc, and have found the benefits of less clutter to be profound.

I never really regret deleting something, but that could be because I try to keep my life simple, within reason, and focus on the future.

I also recognize, as you point out, that there are limits to this -- sometimes there is a genuine need to keep a record. As a programmer, my work is all tracked in git. For a creative professional, I assume that a basic requirement of that sort of job is an excellent backup system.