> Real life is not anonymous and consequence free either, why should online life be?
In real life you are largely anonymous if you go to any place that is not in your social circle. If I go to any physical store under the sun and pay in cash I remain completely anonymous. The only exception is staff checking your ID for alcohol etc. if you look underage, but that datum is only stored in one persons brain for as long as they bother to remember. Many people would take issue if the clerk noted every persons name when getting carded.
> what's so great about having complete online anonymity anyway?
Because liberal governments can always become repressive governments. Unless you have absolute faith that your government will never do something you have a moral objection to, you can never be sure that anything you are, believe or do will not be censored or land you in jail in the future. Infrastructure that has a minor benefit under a "good" government, but would serve as a major tool of repression under a tyrannical regime should not be built out of principle.
As a thought experiment, ignoring issues with technical feasibility, would you approve if every person is only allowed to leave the house, under a stiff prison sentence for violation, if they wear a shock collar that can be activated remotely by a law enforcement official? That way, if police want to arrest you, they don't need to use violence and they don't have to chase you if you tried to run. It would make the police's job a lot easier, would it not?
> If we can make sure that every real person can only have 1 social media account per platform, and if we can check that someone is an adult, and if (and only if) we can do that in a privacy preserving manner... then honestly, I don't see why I would be against that. I'm ok with being held accountable for what I do online
To the extent that political discourse is shaped by astroturfing, realistically it'll just give a monopoly of influence to whoever controls/bribes the company or entity doing the verification. There certainly would be technical/cryptographic solutions where there isn't some central entity with a master key, but I doubt that it'll work like that anywhere, especially if it requires a citizen safeguarding his own keys.
> I want to pay that price to prevent the severe outside interference we've seen in elections and in our politics.
Outside interference in the form of legal bribes (lobbying) and sometimes less legal forms of corruption has orders of magnitude more sway over politics than whatever the public may effect in elections.
> You and many others might not be, but it seems like you've lost the argument.
It's ridiculous to imply that there was any serious public debate on this.