I do acknowledge that rent is a function of supply and demand in the big picture, at least. I don't think the whole foundation of economics is wrong.

Demand for apartments will be constant. Supply of apartments will be constant.

But I think what's going on here is that we are way off the equilibrium point. The supply of good places to rent is far outpaced by demand for them, at most price points, and especially so where all the value is (on the coast). So, this means if you're a landlord and you know you'll owe another $1200 tax to Sacramento this year, you should be very confident that if you raise rent by $100 a month, even if an individual tenant would rather move than pay it, someone who can afford $100 more exists and will almost certainly fill that vacancy promptly. It may represent a slight step down in what their buying power would buy. Like, they may have rented a $3000 apartment before, and they'll now rent what used to be a $2900 apartment from you for $3000.