People will argue against universal healthcare because they don't want to pay into a pool of money that gets distributed among people who use the healthcare services, and they don't like the idea of paying for someone else's care.

So instead they support a system where everyone pays into health insurance, which by definition is folks paying into a pool of money that gets distributed among the people who use the services the insurance provider provides. They're still paying for other people's healthcare, but for some reason they don't see that. It's the same as paying car insurance if you're never in an accident.

And this latter system allows insurance companies to simply not provide coverage for certain care, meaning that you pay into a shared pool of money that no one can use to get that care provided.

Even if you're wealthy; and you can afford the best insurance, how is this better? You might think you'll have shorter hospital times, but the hospitals are still running on thinner margins for profits, so its not like the Doctors are waiting around for you to show up. If there's less patients, they hire less staff.

You're still constantly running the risk of having some healthcare problem that isn't covered, just by the nature of letting the provider stipulate what they do or don't cover.