But one thing that bothers us about private surgery is that if anything goes horribly wrong, the hospital won't be able to deal with it (as most of them don't have intensive care units) and we'd have to be transferred to an NHS hospital. Which was easy enough a few years ago before the ambulance crisis, but now you may have to wait several hours for an ambulance, by which time you could be dead or much more seriously ill.
As we're both in fairly good physical health and have no problematic medical conditions, we assume that the chances of an unexpected medical emergency are pretty small, but even supposedly routine operations can lead to unforeseen mistakes and catastrophes.
Literally tens of thousands of people are dying because they're not getting prompt medical attention from the NHS. Ambulances are overwhelmed, A&E departments are overwhelmed, hospital wards are overwhelmed. We don't want to end up as another delayed-treatment statistic.
If either of us need urgent surgery, goodness knows what decision we'll make. All I know is that more and more people are going private because of the huge NHS waiting lists. They're willing to take risks in order to end chronic pain and get a normal life back.

