Facebook really wants you to scroll past no more than 5 posts. It will chose the "best 5" by some algiorthm, and after that it is mostly garbage. Their best 5 algorithm isn't very good, it finds the most important stuff (a friend had a new baby - these get a lot of likes), but will miss most of the next level down. Then it descends into memes that people share instead of the actual life people live.

Your friends presumably don't post ads. So filter out things that aren't from your friends.

Seeing very similar things in my feed. 4 out of 5 posts are now an ad or "recommended" which only further douses my already very small desire to use Facebook at all.

1 out of every 4 posts is an ad nowadays.

It's certainly higher than it used to be, but I doubt many users would tolerate anything that high. I just did a quick scroll through my feed (first in a while) and it was pretty much what I expected to see. From comments I'm reading in this thread I can only assume FB have been doing some sort of A/B testing. Luckily for me I seem to be in the control group. Maybe because I only check my feed once a week or so...

For me it is literally 1/4 posts are an ad.