"Twitter, Facebook & co could have hired millions of people and paid them magnanimously with the billions they make to scale moderation up."
Nope, run the calculator again. Twitter is barely profitable even with current staff (and your proposal would literally multiply that staff thousandfold). Facebook is a bit better off, but you can't make enough money on ads to support good moderation for a global chatbox of a billion users speaking hundreds languages. Even at a ratio of 1 moderator per 100 users, the payroll would dwarf Meta's yearly revenue.
Nope, run the calculator again. Twitter is barely profitable even with current staff (and your proposal would literally multiply that staff thousandfold). Facebook is a bit better off, but you can't make enough money on ads to support good moderation for a global chatbox of a billion users speaking hundreds languages. Even at a ratio of 1 moderator per 100 users, the payroll would dwarf Meta's yearly revenue.