My parents moved to Scottsdale, AZ and they had a HOA. They could not paint their house any color but white. They could not plant anything without approval from the socialists. The mailboxes were grouped half a block away for the neighbors to get their exercise.....
My uncle lived in Rancho Paloes Verdes near Los Angeles. Built his home on 2.5 acres in 1959. Never voted for a HOA but one came along many years later.
They decided to add 2 walls to enclose a porch. The HOA socialists told them what windows they could have.... mind you not a single person can see their home as it has many trees and is in the hills but they held up the building by 6 months. 6 months for 2 walls because of socialists. This is a weekend project to add the walls. Add a few days for 2 coats of paint and moving their stuff in.
They went thru the same problem with the skylight they added later on.
One year a lady showed up at their home who they never saw before and she told them to clean up the property (to her satisfaction). My uncle said he didn’t change a thing and never saw her again. I bet this lady was to busy being a busybody with the other homeowners and forgot about it.
I think you do have to sign on the dotted line whether that is in a one sentence blurb in your deed or a separate agreement. I have never heard of an HOA just being able to annex people’s property.
The saving grace is often that the HOA is strictly volunteer, and people just don't follow through. Be wary if your community has a paid board or a salaried manager. Then you have trouble.