There could be a difference in numbers, first and foremost: how many friends do you have, compared to them? Especially people that regularly use social media.
It's cost-free and easier to like a new selfie than a wall of text. Pictures are easy to notice when scrolling down, and are pretty uncontroversial: you don't need to think hard about it. Just that will mechanically increase the number of interactions, regardless of the era or country you're living in.
I don't think there's any value in posting such material on social media. Most people typically won't care about the things you're researching, and expecting them to pat you on the back for accomplishing stuff they're not interested in understanding seems more like you're trying to sustain your ego than anything else.
I do understand your point, though; I think it's just a bit misguided. Facebook isn't appropriate as a platform for your kind of content in the first place, and I'm pretty sure their algorithms promote pictures and other interactive media over text posts, contributing to the effect you're complaining about even more. It'd be better to publish your content somewhere people will be actively looking for it: a personal blog, a mailing list, a dedicated forum, or even better, IRL meetings and conferences related to the subject matter.
I wouldn't expect other people to be interested in my landscape photography endeavors at a seminar on the latest advances in nano-materials engineering or East Asia anthropology. You shouldn't expect people looking for some distraction (and, let's not hide it, that dopamine rush from a carefully engineered interaction process) to be interested in thinking hard about things. They probably have other mediums for that.