When I see a t.co (x.co now?) link I have literally no idea where it's going to take me at all and I am far, far less likely to click one of them knowing that it's a url shortener. This is such a common thing that there are browser extensions/slack(discord/teams/etc) options to unfurl urls.
Exactly. I think it also teaches people to trust all kinds of obscure domains instead of trusting only well known ones. It might be even easier to write the little bit longer domain as you don't have to double check correct spelling. Browser will likely fill it in anyway. I just don't see any real benefit.
That's actually surprisingly cheap. I used to be at a 4 letter .com and we paid over $1mil for it in 2015 back when domains were still worth something.