I'm curious, were they ever that stereotypical "shh" environment that movies claimed they were? Because no public library in my lifetime was ever like that (just smaller school libraries), but I can't go back very far. Most libraries I've been to have multiple areas or floors, some which are quiet and others which are allowed to be noisy.
They were "shh" back in the day, but with time they have become more of a place for activity for the community. When I was a kid in the 80s and early 90s they were definitely more strict with keeping quiet, especially in the reading halls. Library history is actually quite interesting, and the whole development of the library as a key element in building and supporting democracy and community, is worth looking into.
Capitalism didn’t kill third spaces, technology did. Niel Postman and Robert Putnam spent most of their lives writing about the creep of technology and how it destroys actual human society and its base-level interactions.
I had to go to IKEA for some furniture during a hotter period in the summer. The amount of people just hanging out and preventing us from actually trying the sofas was really annoying. So yeah, you can do it but it's a bit of a dick move to actual shoppers.
(also fuck IKEA for making their store into a huge maze where you almost have to go through the entire thing even if you just want a single item)
I've only ever been to one IKEA, but at least for that one, there were somewhat subtle but definitely visible holes in the walls and displays to allow you to cut through the maze.
ETA: Also - again, for that one - if you know what particular item you want, you can find that item's location on the website and go straight to the warehouse to grab the item off the shelves.
They still exist in most towns and cities, and if not a mall, a strip mall usually has some inside portion. Smaller with less options, but still fits the bill.
If you sit in a hotel lobby long enough, most properties will eventually kick you out. You can usually get away with it during the day, but you'll start to stick out more the later in the day it gets. At night, the night auditor probably won't even let you in the front door.
Pretend like you belong there if you do need to hang out in a lobby for a while, and don't make a mess.
Yeah, in the states a college campus center is a great place to hang out if you're passible as a student. Some of the campuses are huge and there are multiple places that don't require an ID card