I don’t want to live in either world.
In scenario #1 as you laid it out, Facebook wins, or whoever. The progressives universally win. The entire internet is theirs. In scenario #2, Facebook wins. Google wins. A handful of others. What incentive do I have to choose either?
In my scenario #2 those companies are declared to be public utilities, then subsequently regulated as all public utilities are.
Can AT&T or Verizon cancel your phone account because they don't like your politics? No, they cannot.
How would that be winning for the big tech companies?