What city? Restrictive zoning is definitely a huge problem when it comes to affordable housing in a great many American cities. I guess I can't say it's universal though.

Seattle, and for a city of 730,000 people, it currently has ~13,000 units actively under construction, another 30,000 approved, and another 30,000 applying for permits.

I look out the window, and it's a panorama of construction cranes. There's more active cranes here, then there are in any other American city.

Oh, and my rent went up 17% last year.

Your personal experience does not reflect what is going on for the city as a whole. Seattle rents are dropping significantly and there has been a ton of publicity about it. This article from close to a year ago is representative:

https://www.seattletimes.com/business/real-estate/seattle-ar...

Here is a very recent article:

https://www.seattletimes.com/business/real-estate/amid-build...

If rents are dropping, and the economy is booming, why is the homeless population skyrocketing?

I may not be representative, but the average rent dropping doesn't mean anything to someone renting a bottom 10%-cost unit.

Average rent may very well be dropping - but the average renter is not someone who lives right on the margin of having a home, and sleeping on a park bench.

You're right about the rent on the low end. These things take time. Seattle, like many other cities, under built due to poor zoning policies for years and years. This deficit doesn't get fixed overnight (or in a year).

It'll happen though if current building trends continue.