I've created several bubbles on Twitter by curating lists. One thing I don't want to see is outrage, so I remove anyone who posts outrage from my lists. And it actually works!
I've tried to create a bubble on Instagram of the content I want to see. But Instagram is more agressive about pushing algorithmic content at me against my will. After days of trying to train the algorithm, I got it to only show me real photos of travel and nature. But slowly new things are always creeping in. Liking one photo can set off echoes that are hard to get rid of. If I accidentally like a photo with a pretty girl in it, or someone's sweet workstation setup, or a map, or a meme, Instagram starts filling my feed with low quality junk related to those topics. Even the travel and nature photos are low quality junk. The inability to set up a feed of content I actually want to see (friends and genuine non-influencer travel photos with under 200 likes) is pushing me away from Instagram as a platform.
Facebook's news feed is so bad that I never scroll it at all.
For me, RSS via Inoreader is my new way to curate most of my content. The only problem is that most of my friends don't post RSS friendly content. Including friends in filter bubbles seems to be an area that no existing platform does a good job of anymore.