Yes, I am perfectly aware of how the fediverse works. I was asking for a clarification on what you were referring to, not a technical explanation.

One of these (and the most alarming of which) is that, while removed content was never fully gone from the fediverse (hence why you can undelete comments), you originally had to stalk the whole fediverse manually to get answers, which might take a month.

It's not a 'crevice', it's how the system was designed to work. Any technically literate person can set up an instance in an hour and have unlimited access to any information on the fediverse short of user info. Nobody's stalking the whole fediverse, anybody with the inclination will just self host.