Ok, I must be the weirdo here. I love using FB as a source and frankly, TA can be so helpful. I am not talking about the reviews, I am talking about the forums. If you want to know what bus to take, where the stop is, what transport website to use, etc. etc. TA is the place to find help. It is like this forum but about 1000 times larger.
Do I read TA reviews though? Of course I do. It isn't tough to filter out the fakes and so far, have been quite happy with places I have chosen based on reviews. All of my colleagues in other cities have their listings on TA and I know they don't write fake reviews and I know that I don't either.
YouTube can be great to look at places you might want to visit. There are good videos and bad videos, just like anything else.
How to use FB? Go to the pages from the city tourist office. Every museum and tourist attraction has a FB page. All of them. Makes it easy to see about special events, like festivals. Expat FB pages are great to find restaurants. It is fun to ask what is the best Indian restaurant in Frankfurt and within 5 min. you have 100 answers.
As to chat GPT, I can tell if they are writing descriptions for tours, etc. They are gaggy.
We did have fun this past winter, as I do volunteer work in a WW2 bunker that has really interesting exhibits in it, and we wanted a photo of a bunker covered in snow for the website and tried chat gpt. We got some hilarious results. Mine looked like some kind of Russian palace. Certainly not a bomb shelter.