Indeed. There just aren't suitable alternatives to the big socials out there, though people have tried again and again. I think the best thing to do is to just restrict how much we use them as to not be to anchored to them.
It's important to note that "taking back the internet" is more than just our relationships with social media, but also how we act and behave online and where we choose to talk to others. If you read some of the Yeterweb's mission statement, they make it clear that it's about how we relate ourselves to the internet. It's not just about finding replacements for social media - though a lot of people would like that very much.
To quote some of it --
"The "movement" is a digital movement of people, thousands if not
tens/hundreds of thousands, who are deciding to reduce their
participation in the core web, with some of those people choosing instead to increase their participation in the peripheral web."
The 'core web' meaning the Big Tech socials we're all familiar with, and the 'peripheral web' meaning websites like Mastadon and SpaceHey.
What this statement means, is that this is about who we choose to talk to and where on the internet we choose to do it, it's not as much about where we're going to entertain ourselves.
'Reclaiming the Internet' isn't about nostalgia baiting ourselves into the past, but to simply foster environments online where we can get away from awful people, bots and AI slop to go back to when we were just trying to chill out and get away from the world.
If the content you want to watch is only on Youtube or Instagram, then this is something you can do: You can ghost on the site instead of logging in, then keep all of your subscriptions and content that you like as bookmarks, or save images on your device istead of an account. You can even use frontends or RSS feeds, but that would require a deeper conversation about what you're looking for.
For now, It's best not to look for an 'All-in-one' solution that socials provide, there just isn't the market for that right now (If ever).