It's probably too late for any specific publicly traded company that already exists, but social media as a protocol, with forced interoperability if necessary, is the way to solve this. Many regional phone carriers doesn't prevent people from communicating across regions.
Of course, it does cost more, so the question becomes who is willing and able to pay for a socially less harmful means of networking individuals without having to put them all on a single data hoovering ad platform? Whether it's direct charge to consumers or subsidized by government, the money still ultimately has to come from people.
Implement ActivityPub (an existing protocol recommended by the W3C), and offer their underlying social networking services as hosted and managed software for big orgs to operate on their own domain. With interoperability, they'll work across domains. Target customer is anyone with at least 100K followers (so gov, institutions, media, et cetera).
Of course, it does cost more, so the question becomes who is willing and able to pay for a socially less harmful means of networking individuals without having to put them all on a single data hoovering ad platform? Whether it's direct charge to consumers or subsidized by government, the money still ultimately has to come from people.