Not quite "back to" as there are still ad-free options for Disney+ and various other streaming services. There weren’t/aren’t ad-free options for (linear) television channels like ABC, CBS, NBC, FOX and "basic" cable. At this point, the ad-supported plans are an addition to ad-free plans and provide more choices for consumers.
I use adguard DNS on my Apple TV's and I can tell you it does NOT "eliminate ALL the ads on ANY streaming service".
We only have a couple streaming services that aren't ad-free but I can tell you we see plenty of ads on Amazon Prime Video.