The current version of "meta" account is just reverted back to an Oculus account but renamed. It has the same functionality it used to when it was called an Oculus account. And specifically is missing all the functionality of a facebook account. You can optionally also have a facebook account connected to it if you want the social features, but you don't need them.
As far as I know there are no headsets that don't require an account, as buying games is entirely digital now. The account is how they know what games you have purchased. The only reason to not have an account is if they want to attract users that want to sideload games only and not get them from a store. There isn't much incentive on their end to provide that experience, especially since all the other headsets they are competing with are using the "game console" model, of selling the hardware at a loss, and making it up with software sales. Trying to be the one company that has to profit off the hardware sales too makes your headset look like a bad idea to buy. Even if some people would want that, the VR market isn't big enough yet for that to be a viable option. Too many people are just looking for the cheapest up front purchase, no matter what they have to sign to get that price.
Maybe 5-10 years from now it would be worth doing, but it's hard to say for sure if it ever will be. Imagine trying to launch a new console now that was similarly powerful to the current consoles, but costed 50% more. The upside being that it could run the games of both (somehow legally). That console may sound like a good idea to some of us, but how many? Enough? Probably not. Even selling hardware for profit doesn't mean profit from day 1, you need to sell enough to cover research, development, and manufacturing. Not to mention the salaries of all your employees. So, they might need to sell a million units before they are out of the hole.
Edit: there are VR headsets that are basically just monitors. You probably don't need an account for some of those. But they also are pretty limited in usefulness.