Maybe this isn't very "lemmy" but I think the bottleneck isn't really money, but the stuff you want.
In Australia the main problem with the "housing crisis" is that all efforts to resolve it are on the demand side, and very few on the supply side. Giving first home buyers grants and discounts is great, but that increases demand and increases the price. Removing some of the ridiculous tax benefits to owning multiple properties is great, and has reduced demand somewhat, but it hasn't solved the problem.
To really solve the housing crisis you need a house for everyone that aspires to own one.
In the last decade, having the people able to build the houses has been the real bottleneck. All of the able tradespeople are already building houses. We can't build a million more in a year just because everyone has the money to buy them.