I am a foreigner in Japan. Most of my friend and family members still use FB back home so I still keep the account but I am pretty much out of FB since early this year. No App on my phone and not log in to my account for many months already. I think I should close it for good like you. That platform is so annoying. It also takes info from everyone in my contact book regardless of FB user or not and do what they do best, makes money off it.
IG,
I also worry the greedy FB will turn IG to just another toxic social media like FB. Anyway, I still like it as for now.
I share photos on
my IG page first then copy the image URL to other places (with a little help from browser's web developer tool). IG doesn't offer high-res image than phone screen resolution so people can't do anything much with the photo. (Platform that let people post high-resolution images can not protect the image no matter what.)
What type of audience you will get on IG is largely dependent on what hashtag you often use. Most people in my cycle are very much like photography or want to travel in/to Japan and they are very polite.
There is a lot of account doing follow then unfollow things, just ignores them. In fact, don't even care about those numbers.
What I like most about IG,
I think it is focusing more on visual content. It doesn't matter what they use, phone, drone, video, dslr, mirrorless, even painting.
I don't do online social but I meet people and go for photo shooting from time to time. (as far as I recall, it is 50+ this year alone) Majority of them come from IG. I used to directly offer the location for photographic worthy places in Tokyo on my IG post, but now I put information on my website instead because I can have more details and walking map there then leave site URL in the profile.
Some people are interested in my work enough to take a photo trip with me which I just start 2-3 months ago. Some didn't reserve a trip but send me a thank you message and offer to show me around their town if I go there
And many more simply want to talk and exchange photography knowledge. All in all, I learn many things from each meeting and conversation.