Instagram in particular seems to have gotten much more aggressive in not letting you view anything without an account.
For whatever reason though businesses like restaurants and bars will often nominally "have" a wide range of social media accounts, Instagram is often the only one with actual content. I used to be able to reasonably use these but I now seem to get a wall requiring login immediately.
It's possibly/probably worse because I'm often doing this in incognito mode, which tends to make everything more aggressively naggy. Twitter seems to be fairly random as to when they'll let you, say, view replies or media or something without requiring login, while Reddit is basically fine on desktop (even better in the "old" mode) and a dystopian nightmare on mobile.
Pretty much everything "big" is much much worse on the mobile web, I guess because they figure they stand a pretty good shot at getting you to get The App instead. It sucks.