[InsideOutSanta]

"Because not everyone wants to pay for the same class of service."

Countries with socialized healthcare systems usually mandate a basic level of service, but you can then buy additional insurance on top of that. That's what the NHS is, it's the basic mandatory service everybody has to have. But it's not all you have access to. You can get better healthcare if you want to.

In the UK, this type of additional healthcare is also sometimes provided as part of a job benefit.