I'm pretty sure I and some others had a 100% run. What happened to them?

I got in an argument about the quality of a speedrunner. I have the opinion that a good speedrunner has very little to do with the difficulty of the game. To be good in an easy game like 'Super Mario Bros.' is as hard to accomplish than becoming good in hard games like 'Cuphead'. The biggest factor imo for the quality of a speedrunner is the amount of players in the game. Or in short, more players equals harder speedrun.

His opinion was that if you are good in a hard game, you have more accomplished than being good in an easy game. Or in short, hard game equals hard speedrun independent of other factors.

What do you think?