1) Mastodon

Mastodon is the social network that’s perhaps gaining the most traction in the wake of the Musk Twitter takeover, and it’s the one that offers the most Twitter-like experience, as well. Take a look at the Explore page and you’ll see what at first glance could be a reskinned version of the Twitter homepage.
One of the appealing aspects of Mastodon is that it’s decentralized, so it can’t be controlled by a single entity. It’s made up of multiple servers (or “instances”) that are managed by users, and that means it’s a bit trickier to sign up for—you have to choose a specific server to begin with, for example, and you can even create your own.
It’s much more bespoke in terms of topics, communities, moderation and funding (with server running costs often crowdfunded through Patreon)—and it’s also of course much smaller, which means less content on the topics you’re interested in. If you’re willing to invest the extra time and effort, though, you might well find that Mastodon gives you the Twitter-but-in-its-early-days experience you’re looking for.