Or maybe you value the consistency of full enrollment that comes with a waitlist over the additional revenue you could earn with higher prices. Could be the case if there are high costs to changing the size of the business.
Imagine there’s a law that you can only have 4 children per caregiver. Your capacity is 8. Lose one and your revenue is down 12.5%
You can't criticise free markets where there is no market, let alone a free one.
"Supply and demand" is not a free market claim, it is accepted by everyone.
I'm just pointing out that the NHS exchanges monetary cost with temporal cost - you're paying with your time rather than your dollars, for access. You're also paying dollars via tax, but that's unrelated to access.
A nation can accept or even demand this trade-off, and many do - but support tends to drop when it is made explicit.
How so? This doesn't have much to do with a free market.
The same applies if eg the government provides a service for a fee, or otherwise gates access to something. Eg H-1B visas to the US should arguably be auctioned off.