Honesty the best thing I can do is to build more units on the land I own. That is challenging though so it takes time and capital.
You can thank single family home zoning and how difficult the city makes it to build for the rising rents. The landlords I know are very pro building. 14 units is more income than 4.
Rents are being affected by every investor, including those that own only two houses. Perhaps more explicitly by large companies with hundreds or thousands of properties, perhaps not. I've certainly spent enough time on threads in which people who own only a single rental property in addition to their own home compare notes on how to raise rents for more income in their pockets.
With all of the regulations, risks, and high interest rates forced on landlords, I am wondering what you mean by "unfairly"? One bad tenant in Seattle, could mean months without income and even massive property damaged with no ability to recover damages.
As a small time landlord (I rent a few rooms in my primary residence), I feel that the rent I can charge is way below the risks of a bad tenant.
I think this is only possible when large scale investors 'corner the market' by buying up a large percentage of homes in a given area. They can then control the rents because there is little competition.
On the other hand, if nearly every rental home is owned by a separate investor then each owner is competing with all the other small investors for tenants. They have competition and might be forced to keep the rents lower.