There was briefly a log-in nag popup that would appear on scroll.
That disappeared and Musk got lots of praise for it, probably entirely unwarrented but it was basically the only thing that improved post-Musk. Then it came back with a vengeance.
What? No it wasn't! You used to be able to view entire Twitter threads without being logged in. It was also possible to go to someone's account page and see their posts in reverse chronological order. The latter went away shortly after Musk took over. The former took a little longer, but is now gone as well. In many cases you can't even view a single tweet without the site trying to get you to log in.
I remember it being the case before too. It wasn't unconditional like it is now. For example, I distinctly remember being able to scroll through someone's profile in a normal browser window without being logged in, but in an incognito window, I was immediately told to log in or create an account.
They may have had other heuristics too that led to inconsistent behavior between users. So it should not be so surprising if some people report that that happened even though it didn't happen to others.
