One of the big things with a free market is that it assumes everyone is out to screw everyone else. Buyers want minimum prices, sellers want maximum. In principle, it all cancels out. Unfortunately, the information and power balance is also assumed to be even. In practice, it’s not. It also requires both parties to be able to walk away. With housing, that’s not an option.
Home assistant, ESPhome and Tasmota form a core of this. The self hosting community also has a strong mindset towards security.
The stuff I self host is mostly because I don’t trust the “free” services a lot of techies seem fine relying on. I’ve seen too many providers suddenly go belly up, and screw people over.
I also use defence in depth. The “S” in IoT stands for security.