That's the hard part. I imagine most homeowners are of the idea "I got mine, who cares about anyone else?" We see this line of thought in many parts of politics. Honestly, I'll take a bath on my home value if it means my kids, their friends, my niece, etc. get to secure housing. I don't care. Hell, I might find myself in a hard spot in the future and I don't want housing to be an issue. Housing is so important to one's dignity, ability to work/access some services and safety. There's no reason people should be collecting houses like baseball cards.
No, it's pretty clear that insufficient supply in certain areas has led us here. Treating housing as an investment is just a symptom (it's really unavoidable if the good is scarce).
We need to limit land value increases.
A land value tax helps with that. Increasing supply by upzoning might help even more.
This conspiracy theory that people who own real estate are limiting supply so their investments go up is not reality. People indirectly want to limit supply because they enjoy their neighborhood the way it is. It turns out what they enjoy about their neighborhood others enjoy about the neighborhood so the price goes up. It doesn't mean that they are overall goal is to increase the value of their house. The evidence is that adding public transport and rezoning to higher densities and commercial use would increase the value of their property a lot but most oppose that because that is not why they bought in the neighborhood.
It’s pretty clear that treating housing as an investment and not as a fundamental right has led us here.
Unless you’re invested in real estate in which case your incentives are to keep the system in place.