I did a test as well. Unlike most people, I've set up relatives very well. Yet not a single post by a relative and some of those have high engagement! All kinds of Instagram Reels and ads and a bunch post from people with high a high absolute engagement, but historically a very low one from me.
So, this obviously is a poor filter, which does not keep me engaged and which proves that Facebook is NOT a social network as to be social, it needs to act as such, and I never hear from my closest people over there anymore!
How hard it is to see that a post is from my mother-in-law and multiply its weight by 100, or one from my sister and multiply by 1,000?
Another thing that Facebook never puts any effort into is photos of children under 13! They had a feature called "scrapbooks" where you can create profiles of your children with the promise of those turning into profiles after kids turn 13. Well, they've abandoned this feature and people kept tagging children as their parents! Not sure how this served their facial recognition, but it inconvenienced us parents!