I know there are people who spend all day with 30 phones in front of them posting online for work, but there's got to be more sophisticated operations that write and post hands free, right?
About what % of say, twitter for example would you reckon are literally just computer generated and posted?
Depends on the site. Twitter probably has a lot.
Places like Truth Social, for better or for worse, probably won't, because they want you to sign up with your phone number, etc.