I for one have stopped posting any content to lemmy.ml communities.
Assuming that these settings are a universal part of lemmy and not instance specific, I click my name in the top right corner, select settings from the dropdown, and then there is a page with 2 tabs, one saying settings and a second that I can switch to called “blocks”. In the blocks tab, I can view and add to lists of blocked users, communities, and instances. Just go to the instances drop down, and search “lemmy.ml” and click the option that appears to add it to the block list.
Tbf that doesn’t actually do much at all in terms of blocking an instance, hence is horribly misnamed imho. All it does is mute communities located on that instance. The users from that instance can still harass you in posts in other communities, triggering notifications, vote on your content, etc.
The Sync and Connect can do true user-level blocking of any instance you choose without needing admin support, and the Lemmy alternative PieFed, or e.g. Lemmy.cafe or dubvee org have blocked all of the big 3 tankie instances.
