> HOAs are often tied to a piece of land, with it being mandatory to join if you buy the land.

Legally speaking one is often not buying the land but rather buying the unit. The land on which the unit sits is owned by a corporation (HOA), and as a condition of the lease you must abide by the corporation's rules.

* https://en.wikipedia.org/wiki/Leasehold_estate

If you don't want to live by an HOA's rules then don't live on the HOA's land, but rather your own land:

* https://en.wikipedia.org/wiki/Freehold_(law)