I think you're definitely misunderstanding what Instagram is. I'm not saying it isn't user hostile and full of ads, because it definitely is, but you're complaining about all the wrong things. All of those things you're complaining about are conscious design choices and have been from the very beginning.

Instagram is not some generic photo sharing software that tries to be open and modular and integrate with everything and proliferate arbitrary visual media with a rich tightly coupled messaging system. It was never that and won't ever be that.

Instagram from the start was just about taking low res pictures with your phone camera, putting a filter on them so they look less terrible and then sharing them with your friends. Every other feature was begrudgingly added to increase accessibility and hence DAUs. So you were never supposed to be able to interact with anything outside of the app. You can't cross-post your posts to facebook or twitter, you can't post from your computer, you can't spam links in your photo descriptions. All of this is literally the point of Instagram. It was like this before it and slightly after it got acquired and people loved it, not in spite of the restrictions, but because of them.

Then Zuck crammed it full of ads and a terrible glommed on messaging system and ruined it.