It’s not about them seeing my posts it’s their ability to interact without my knowledge since different types of harassment can be quite harmful even if you don’t see it (i.e. lying, disinformation, accusations). So it’s not in my best interest to block people on a platform where the block system treats the threat of these people as non-legitimate by allowing their continued interaction and replies.

I hope they write me a lot of long and nasty messages that I never see.

I sincerely hope you never meet with any of the more elaborate trolls or bad-faith actors who use more aggressive tactics like accusations or disinformation against you. This can be very harmful, even more so if you cannot see it and respond to or report it, especially reporting it. Also a lack of reporting and substituting reporting for blocking can be harmful in the long run because when users are not reported, they may never be actioned by mods or admins. Which is awful for the health of the community, maybe you think others can report for you but bystander effect is real and the people who think this way eventually compound allowing trolls and bad-faith actors to operate longer if not indefinitely, so it doesn’t benefit anyone to hide them and pretend they don’t exist.