Some people just don't like cities. Google pretty much any major Western city and you can find comments complaining that it's dirty, riddled with crime and has too many immigrants. Paris is a real place, not a theme park.
Paris was much better 20 years ago; sure it still smelled like pee (no idea why it was and it is such a problem in Paris and literally nowhere else) but nothing was wrong.
I've been in 2019 and that's the last time Paris will ever see me: immigrants touching you trying to sell you stuff, people defecating in front of the supermarket in broad daylight, homeless camps, I've had a drugged up homeless jumping on me.
If you take a reasonably long historical perspective, Western cities are a hell of a lot cleaner and safer now than they were in the past. Sewerage goes a long way.
Encampments have an big and long history in Paris even after the 2nd world war... It's not great, just people looking for a better place to live and survive.
