If you can't stand facebook, you don't have to be on it.
If there's aspects of facebook you like and find useful, but some people do your head in, you don't have to be friends with them.
If you feel a social obligation to be FB friends with family members, work colleagues, particular friends etc, but turns out what they post on facebook annoys the crap out of you, there are several ideas for avoiding these posts on this thread while still being 'friends' so you don't offend. Shift them to acquaintance list, unfollow them, hide individual posts, just scroll past, etc. Several people on this thread have said they have done extra filtering and feel much better for it.
If you keep reading posts you find cringey, vomit-inducing, sickening, and that make you sad, you need to have a good think about why you're doing that, IMO, when it's so easy not to. If it's to get more ammunition to judge a particular person for example, that sounds deeply unpleasant.
If you then take that a step further and start criticising the whole site and the many people who harmlessly use it for sharing the people, places, things that make them happy, when you personally haven't done anything about making your version of it work for you, you're a muppet. Not in a good way.