> if interest rates being high was making housing unaffordable, one would expect prices to be down.

I think you have to be careful with the definition of "unaffordable".

Housing, at this moment, is unaffordable in the sense that the cost of housing squeezes many people's discretionary budget, savings, and even sometimes the budget for necessities. It is not unaffordable in the sense that (most) people do have enough money that they can pay for it, even though paying for it might cause them hardship elsewhere.

Housing is an inelastic good - particularly for demographics who have limited access to transportation and therefore need to live very close to where the jobs are. The price increases until it consumes all the money available to pay for it.