This would be akin to the Nazis winning WWII and the last rabbi is in hiding but still dressed like an ultra-orthodox on his way to temple.
To help understand what the Jedi were like look at it as a rabbi with the honor code and sword fighting techniques of a Samurai.
Another thing to reconstruct is the line “I haven’t gone by the name Obi-Wan since, oh, before you were born”. This would mean that Obi-wan left the Jedi Order before the fall of the Jedi and would explain how he survived it.