In a hypothetical socialist utopia with rigorously defined and enforced guarantees of rights and liberties, government-owned platforms can and should replace corporate-owned ones.
Imagine a concept like facebook/instagram/twitter, except it's open-source and transparent, and its users are in control of its governance through direct democracy and collective ownership. Plus a set of rules defining explicitly what they can't do, including all predatory, coercive, manipulative, and profiteering practices that are the industry standard now.
Obviously it's not a simple solution. Government control ≠ fair, equitable, and transparent. That's why I framed this as a hypothetical. It requires that socialist utopia, collective ownership, direct democracy, and open-source format. But it is possible, and we shouldn't let our imaginations be hampered by what exists today, in this system.
So many things could be done better with centralized planning, but that depends on who is in charge of that planning. And that's why we need direct democracy and collective ownership. Those things can actually be enabled by technology, despite the fact that technology is currently being used to hamper it.
Like, report a pothole on your maps app, and the state repairs it within a week. Go to the open forum section of your social media, and discuss the items on the upcoming bill proposal with the members of your community. Start a citizen's initiative by filling out a simple form that's accessible to everyone and posting it in the right section of the platform. Audit your local government's budget/expenses as easily as navigating to the right tab.
There's a better way of doing the things we're already doing. We just have to dare to imagine, to believe, and to persevere until our vision becomes a reality.