I use Instagram for my hobby/business (coin & paper money collecting & dealing). I have mercilessly curated my feed to be ONLY people who post content purely related to the numismatic world. No real-life friends, no travel posts from random semi-friends, no selfies, none of that garbage. If someone starts posting it, I unfollow them.
And for the ads -- I click on ads related to cat toys and pet food, just to let the algorithm know to feed me more of it.
SO: My instagram feed is 100% hobby-related posts & cats. I think I may be victorious (for the time being....).
PS: Stay AWAY from the "Explore" tab. That is an endless dopamine well of misery.