That didn't really answer the question, however. For the rent to increase, implies that the landlord was previously leaving money on the table. Why would they do this?
I don't think rising costs to the landlord always results in rent increases. Rents are constrained to an extent by the average salary of the area.
If you incur more costs, but the average salary of your area doesn't rise, and you increase rent prices, you run the risk of void tenancies.
Because if they did, another landlord would undercut them. But with all the landlords facing rising costs, another landlord cannot afford to undercut. Hence the rents all rise.
This is how supply&demand curves work.
Over the last few years, Seattle has added many various laws that are costly to landlords to comply with. This corresponds with a decline in affordable housing. I'm pretty sure the Seattle Council is well aware of this connection. But as the number of renters far exceeds the number of landlords, they know where the votes are, and they sell the fiction to the renters that the landlords will pay.
That's not really how it works though. We've been renting out in a lower-cost area in CA since 2018 and in the first two years the average Zillow and Craigslist rental listing went from $1200 to $1800. Why? There was no visible gentrification, that neighborhood really didn't change. Most of the tenants are in construction labor and management, truck driving, nursing. etc. Their salaries surely did not go up by 50%, but the going rate for the rentals somehow did.
I don't think rising costs to the landlord always results in rent increases. Rents are constrained to an extent by the average salary of the area.
If you incur more costs, but the average salary of your area doesn't rise, and you increase rent prices, you run the risk of void tenancies.