Do you have a criteria for what qualifies as block-worthy offence or are you just doing it when you feel like it?
Bonus question: how long is your block list?
I think that making blocks visible only for admins could work. At least the admins of the instances of both users.
I’m not even really sure how big of an issue blocking abuse really is in reality
I’d say it’s concerning, specially due to hit-and-run tactics - replying to someone and blocking them before they have the chance to counter-reply. I used this a fair bit for shitposting and taunting circlejerks*, but it could be easily used also to make the other side look like lacking arguments (i.e. for public manipulation of views) or also for individual harassment.
One of the counter-strategies that I’ve seen was people editing their comments and highlighting that they were blocked. That only works when the person knows that they were blocked.
*my last years in Reddit weren’t exactly “contributing” with that place.
I think this type of two way blocking makes it particularly clear when the person is blocked since it disallows replying and on Lemmy community bans are visible. So editing comments can help with that, as it would be apparent they have blocked you, the UI could be changed to reflect that either by highlighting the user who has blocked you or greying out the reply button. Of course that could be used as an abuse tactic but since it depends on existing replies which are finite it wouldn’t be as bad as them being able to continue making more.
Also since administration on Lemmy is much more in touch with the userbase (at least most of the time) it’s easier to get such abuse dealt with at the community or instance level.