On: Twitter/X will let people you've blocked see your ...

[nickthegreek]

Its not everything, just almost everything. You don't need to be logged in to view a tweet from a direct link.

[falcolas → nickthegreek]

In some cases yes you do. It depends on how the account is flagged, I'm not sure what the flag is, but valid links can and do return a 404 if you're not logged in.

You also can't view replies or context for individual tweets, which makes seeing one tweet next to useless.