I'm in the same boat as you in that I need Instagram for work. My approach is to create a separate work profile in GrapheneOS. I handle all of my mobile work apps in that profile using a separate VPN from all other profiles. I don't expect to be completely free from tracking in this profile, but for my threat model I don't mind too much. Any web queries I make in this profile I keep strictly work related.
People arguing you just shouldn't use Instagram need to remember Instagram is a tool just like Windows, Adobe, etc. Sometimes you need a specific tool to do your job and I believe as long as you containerize that aspect of your life then you'll be fine.
Just don't use your work Instagram for personal stuff, not even browsing memes.
You're right. I always thought Peertube was another YouTube frontend.