I don’t thnik his reaction times have diminished; he had a big moment in Monaco during practice and he was on it in a heartbeat. I just think his race craft is rusting, it’s still Schumi who doesn’t like to let anyone by anyway, he’s struggling with the tyres, he’s had three years out and although he’s stayed fit an F1 life will still be up a gear for him, he doesn’t like the car (although he used to be known for driving around a cars issues but this one is meant to be understeery) and the field is so much more competitive. At times he’s only been a few hundredths off his teammate I think and that’s not bad for someone who has just came back.
Also it took Lauda time for a title I think even if he was immediately quick and Prost had easily the best car. The other comebackers are forgettable so I think he’s doing an alright job.