To the first part, I meant that the range of possible worlds is very broad. Resources aren't a limiting factor. Facebook could continue to do facebook regardless of financial burdens placed on them. If not, someone else can. This wasn't the case for most monopolies of the past. In the past, there was a real concern of "oops. We killed smelting. No more steel."
To the second part... I don't have full answers. I would like this scenario play out to a free media outcome. Decentralisation, and ideally, a lot of commercialisation too. More wikipedias, WWWs. Fewer FBs. Disintermediation. Commodification of bottlenecks like youtube has... owning the relationship between video maker and video watcher. The ideals that made the internet work in the first place.
That's not something a politician can give us though. No one decided that wikipedia or WWW would win. It happened. What I want from politicians is a laundry list:
(1) Trustbusting. The Facebook's acquisitions of whatsapp & IG should never have happened, for example. Youtube should be split from Google (and adwords from search... off topic).
Also, modern antitrust needs to recognize the economic realities of these businesses. This isn't a railroad monopoly or Bell. There are no capital costs and there is no major danger of harming the public interest by sinking the industry. Social media will exist whether or not FB is worth $1trn. That money does not represent "capital" in the productive capacity sense, it just represents earning potential.
(2) Different rules for giant companies. Rules should apply only to designated giant companies. The biggest problems are size related. Be explicitly skeptical of size. Data laws. Copyright enforcement. User content liability. Fairness requirements. etc. A normal regulator will enforce the monopolies which create the underlying problems. We need an explicitly "large company" set of rules, including tax rules.
(3) Much stronger fair use and public domain rules. A complete rethinking. Eg, if a politician gives an interview... this should be public domain or under extremely strong fair use protection.
This is another area where we need to consider modern economic realities. For said political interview, you could preserve most of the financial value (and incentive) with a copyright limited to one week.
(4) Non-consumer rights in regards to monopolies. If facebook, youtube or amazon ban you, this is a public matter. It's more akin to blackballing than "please leave this bar." Everyone needs protections from monopolies, especially non consumers. Once companies are in that size range, they need to
(5) Data use transparency laws. FB political advertising is an extreme example. Half the shit they do wouldn't stand the light of day. Some of it is borderline treason. Shine that light. Full data dumps of ads, targeting criteria, etc. Publish ad matching algorithms. Give the public access to everything the advertiser has access to...
... the list gets long.