Once you get a championship, the run is successful.
How many good to great teams never won a chip (Nash Suns, Harden Rockets, 90s Knicks, Dwight's Magic, etc)
Not many teams repeat or win multiple chips in a small timeframe...that's reserved for all time great teams (MJ's Bulls, Bird's Celtics, Russell's Celtics, Spurs, etc)
The Bucks aren't an all time legendary team...they're very good and capped off their run with the title in 2021. You gotta put this in the context of an entire sport's history. Bucks since Giannis' rise have been successful.