True, there is these two official competitive formats in retail called 3v3 arena or m+ where you can even qualify for tournaments for maximum challenge. The unofficial competitive format for classic is speedrunning. Again if you only like official competitions your opinion is valid, but it's just an opinion.
- - - Updated - - -
I don't wanna get involved in this dumb discussion but can you fast explain me why amount of mechanics is good indication of difficulty?
Like seriously that argument in itself is so dumb because you can make 100 mechanics in a fight but none of them are ever lethal and you got in your eyes complex fight, but you are guaranteed to complete it since you can't die.
edit: btw chromaggus has 12 mechanics so maybe it's one of the hardest bosses ever :O