I think you underestimate the effort / work being a landlord. I’m not a landlord myself, but I own my own house and I know how much effort it takes to do upkeep or even to manage others to do the work.

Yes, people usually want to make the most money. And if we shift to government ‘free’ mortgages for everyone to build (or hire people to build) their own homes, then there will be many people who take advantage of that situation too. Either way, regulation is needed to keep the system on track.

The capitalist system encourages people to invest in other people’s housing - this is not an inherently bad thing. It can find efficiencies that governments never would. Housing is special because everyone needs it, so regulations are needed to ensure the market force efficiencies work for the benifit of the population in general. Government should provide for a baseline housing for all, if not for moral grounds, simply because it’s cheaper than dealing with the costs of an unhoused population. However once we get to the next level up of housing comfort that people reasonably desire, a market economy can work well if properly regulated. As they say, from a pragmatic point of view, capitalism is the worst system except for all the others.