I think you should listen to the podcast from James Allen. He talks to Frank Dernie who provides great insight into the kind of effect MSC had with his work ethic and levels of preparation. While I agree with you that "preparation standards" for drivers would have evolved even if MSC would not have been around during the 90s, what he did was bring in a revolutionary change in driver mentality with his work ethic and the level of preparation he demonstrated for each race.
When you have a game changer coming in, the opponents are forced to lift themselves to that level just to compete, and if they don't they are left behind.
Although I agree with the work ethic, schumacher's mentality to racing was not all positive.
To their credit many of MSC's opponents didn't cheat, use bully tactics or demand special treatment, hence they were left behind. A cheating Senna and Williams team would have left Benetton in the dust. Williams didn't even appeal the foul tactics he used at the end of 1994 (something that would instantly be investigated today) with respect to the two dead drivers that season.
Even the father of his own team mate called him a cheat.
Schumacher also owes 2 of his titles to special tyres that no other team were allowed information on, let alone have access to. To the contrary, Senna always wanted to test himself without anything untoward.
His complaining about the latest tyres just about sums up his petulant character and career.