> wouldn't I just help create another all powerful gatekeeper?
No. The biggest claim of Brave is that all of the information for ad matching is in the browser. So they can not control it. The only thing that Brave can control at the moment is the on-boarding ramps - i.e, if you want to take your BAT out of their wallet and to your own, you need to go through KYC via Uphold.com. But you can pay and contribute BAT to other people even if you haven't done KYC.
Even in this case, the KYC that needs to be done is only with Uphold. After you take out your tokens you are free to spend them however you want and no one will ask you anything.
> I don't believe cryptocurrencies will work
They already do.
> regulated just like other forms of electronic payment, including know your customer rules.
Even in this libertarian nightmare that you are imagining, crypto would more likely help you to keep your data away from businesses and third-parties. If every transaction needs to be authorized and monitored by the government or central authority, then there is no need for the business to collect any information from you - all they would need is to ensure that you are sending your payment from a government-validated address.
Governments don't do that today due to the sheer costs of trying to run such an operation. But tracking things on the blockchain is reasonably easy, so there would be no need for banks and third-parties to do the dirty work for them.