My ideal social network would have the following:
1) Mandatory verification of people: I know there are benefits to anonymity. And there should be places on the web that allow that. Most social networks already do. But there are disadvantages too. A lot of the trolling and hatred comes from people venting behind the veil of anonymity, knowing there are no repercussions to their words. If everyone was verified as their true identity, conversations would be more civilized.
2) No deletion of posts: In the age of disappearing messages and 24 hour stories, we lose accountability. Just like Twitter doesn't allow anyone to edit tweets, I'd like a platform where your posts stay forever (unless the person wants to delete their account and move on). This brings accountability. If I choose to say something stupid about the spread of a pandemic.. or make racial slurs at some... let that content be available for my friends, family and future employers.
3) No censorship. At all: The above two points I'd put in place, just to achieve this. Censorship by definition, cannot be unbiased. People's own political views, likes or dislikes, religious leaning etc... will invariably impact what gets edited and what doesn't. But if we have verified accounts and non-deletable posts... hopefully the dick pics will remain in the minority.
4) Not available for kids: This would be a bummer I am sure. But any place that has no censorship shouldn't be exposed to kids. User verification would allow for this to be enforced.
5) Paid service: People are smarting to the idea that Linux fans have known for a long time. The true definition of "free" is freedom of expression. Not free as in "free beer". If I am receiving a service and not paying for it, I am certain I am the product. Maybe not immediately, but the monetization will follow. So make payments mandatory for all members. Initial tiers can be made more affordable. I dunno, maybe 2 dollars a month. Additional services can be higher. It might not end up being a replacement of Facebook with a billion users. But you'll end up with a more engaging community with quality discussions.
6) No advertising: This means you don't need to collect, or use data of people's preferences and posts. It makes you instantly more trustworthy. Plus the paid service makes the business model sustainable.
7) Company accounts: Let organizations own accounts and post stuff. But lack of advertising means they can't put something on the top of the feed. Unless it organically gains traction. Company accounts would probably pay a little more. Especially because they know they aren't reaching out to 1 million accounts that include duplication, trolls and inactive nodes. They might reach out to 200,000 people but those are "real".
Just some thoughts of mine. Not sure if it makes sense.