p.2 #1Advice on building a follower base on Instagram
The Instagram algo changes a lot. What it rewards pretty steadily is activity: liking and following others as well as getting activity on your own account. And yes, it heavily prioritizes video right now. It really does take a LOT of time.
Hashtags can be good and can be bad. Every now and then there will be a "penalized" hashtag (there is a huge ever-changing soup of these) and you can get downgraded/removed from the discovery feeds for using something as seemingly innocuous as #streetphoto. So, it's a hard place to win.
You've done great - you have a lot of followers in terms of photographers on Instagram (although at a quick glance you also have a fair number of bots/unreal accounts, which isn't your fault as they follow hashtags, but it can hurt you in the algo). If you want to have a societal impact in terms of STEM I would agree with many of the other posters - there are other ways.
p.2 #2Advice on building a follower base on Instagram
Don't know if the OP is still around but he has done quite well with gaining IG followers. I say that because in my original response I said he was HALF way to 10K followers. Now he's at 9K+ which means that since this was originally posted he has gained 5000 more followers!!!
Maybe the OP can come back and tell us how he gained those 5000?!?! LoL
John
p.2 #3Advice on building a follower base on Instagram
This may or not be helpful but if I was trying to get a following or sell photos in todays digital sphere I would focus on NFT. Virtual markets are the future to a degree and currently a train that is still in the station as far as potential. I also think push towards Metaworld thing by insta owner will push digital imaging to new arenas, offering new opportunities.
That doesn't help you break the insta gang but it might point you into a direction that can potentially be of some benefit.