You're just describing how the fediverse works. One social network that is partially comparable with another network. Like subscribing to pixelated from mastodon, etc. not all features are available, but some are. Not only is there no such thing as a neutral platform, but the decentralization of mastodon and the fediverse in general is specifically to address that.

The danger of meta is their data scraping - something they can already do anyway without their own servers being federated.