I'm not against people having a second or third home, as I don't see the class above mine (a farmer getting a side hustle from his family house now that his kids have moved away) as particularly threatening or exploitative.
It's the faceless class above that I hold issue with, coordinated rent seeking behaviour to the degree of being able to fix prices in an area. These do tend to be in the "10+ homes" category
Not everyone wants to own a home. There are lots of people perfectly happy renting as long as they aren't being dicked over on the lease. For example, I don't want a yard and property I need to manage. I don't particularly want to mow a lawn or tend a garden and I certainly don't want to deal with an HOA that might force me to do so. All of that can be avoided by living in an apartment. I am totally in agreement that owning for profit property is pretty shitty, but I don't think it makes you equal to the likes of Blackstone and Vanguard