The vast majority of people using Bluesky don't use a 3rd party or self-hosted PDS because they aren't and probably shouldn't have to be aware of it. It isn't even a prominent feature. At least with Mastodon, it's a big part of the culture at its' core... you don't see this with the official app even.
I didn't even know that was even an option until you mentioned it. I only know that there have been banned accounts on the official/default one that didn't even post anything yet.