Definitely sounds like a USA specific issue. In Australia we pay for GBs data, it's up to us what we use it on. I'd be appalled if they tried to pull that bullshit here.
Most carriers include 'unlimited' data, usually broken up in XXXGb at full speed, then unlimited data at much lower speeds.
It's a rather sad state of affairs. I have 2 accounts, one for professional network and SFW interests, plus another for porn. The professional network and SFW interests has become an absolute bonfire. I find myself using it less and less. I used to check every day, now I barely check once a week.
TL:DR Twitter is only useful for porn these days, and even that isn't fantastic.