I'm really confused by "average, middleish class people who normally would have bought a porsche or a tesla" - is that a typo? Did you mean "would not normally"? If not, your idea of "average middleish class people" is really oddly out of whack.
Many people by homes because of a calculation that owning a home is cheaper in the long run than paying rent over that same period of time. Many people buy homes not based on such a calculation and simply because they have disposable income and owning a home is nice. Many people also buy homes based on neither financial decision-making nor disposable income, and I seem to recall this having some negative impacts on our economy a few years back, which may make it a poor analogy to why it makes sense to buy a Tesla (or a porsche?!) without disposable income.