... $50 million dollars a year?
Construction costs for a single unit of an apartment in Seattle average $300k, on the low end.
Thats about 160 to 170 units for $50 million dollars, if they're all studios, less if there's a mix with one bedrooms and two bedrooms.
So, if they're buying existing apartment complexes or townhouses or something, maybe they can get that up to 200 units?
Meanwhile there are at least 16,000 homeless people in Seattle, and half of all housed Seattleites (380k ish) pay more than 30% of their income toward rent.
You'd need something like 100x or 1,000x or 10,000x this level of spending to make a meaningful impact, otherwise you're just making the equivalent of a couple more Section 8 buildings with 8 year waiting lists.
Or, even better, additionally, massively tax landlords that don't basically follow a rent control schedule, and emminent domain any buildings with landlords that won't comply with a lower profit margin, and massively finance new construction of public housing construction, thus actually turning housing into a public good, instead of continuously using the language that implies that that is what your goal is while not doing anything even remotely approaching that.
Seattle has at least 70k households making below 80% AMI, about 45k households below 30% AMI.
AMI is about $120k.
For the 45k households making below 30% AMI, that means you need 45k units with rent at or below about $900 a month for them to not be rent overburdened (>30% rent to income ratio).
For the 25k between 30% and 80% AMI, that means you need 25k units with rent between $900 and $2,400.
Adding a max of 200 units at probably about $2.2k - $2.4k monthly rent does nothing.