In Seattle there are a ton for town homes being built, split lot and connected, most without any hoa. When they need work I bet you’ll see a lot of neighbors suing neighbors to fix and replace shared elements. I would never move into shared living space that didn’t have some sort of hoa to manage any the shared space.

As someone with an interest in the Seattle market, I'm wondering if one should consider Mercer Island preferable to Seattle to rent or purchase a residence. Do you have any insight?

Very different places. Lived downtown for 15 years. Never been to Mercer island as it pretty much only residential and hard to access. Those can be good or bad depending on the person.