I don't really understand why you have 400 friends on social media, especially if you don't want to see those people's photographs and comments particularly.
Social media means what it's called - social. The sharing and commenting about your own and other's lives.
But I'm much more choosy with my social media friends. I only have people I know pretty well in my current life, people who I am happy to share my life with. And people who's lives I am interesting.
I don't have past colleagues who I hardly know, or school friends I've not spoken too for 30/40 years. I have no strangers. I only have people I'd be happy to speak too in real life.
I do have a very very small number of 'tactful' friends, such as family that I can't really exclude. These are set to 'acquaintance' and unfollow. Their posts don't show in my feed and they don't see most of my posts either.
I follow a handful of specially selected groups/pages, mainly linked to my job or very close local area that are useful to me. I don't use things like market place, etc as I am not interested in selling/giving things away that way. I sometimes follow places we've been/stayed for a while, often just before or whilst there/going, but unfollow afterwards to stop my feed being full of irrelevant posts.
This way I don't actually need to keep scrolling and ignoring posts about stuff I don't want to see from strangers.