I disagree. For beginners, I think doing multiple reps of squats, sit-ups or pushups can be beneficial; especially as a foundation for more difficult exercises.
I am not talking about beginners, but in general. 10km in comparison to the 100 push ups etc. is on a different level. Somebody who can run 10km each day should be able to do 100 squads without a problem, probably even in one go.
100 push ups, sit ups etc. every day - not in one go - is not alot at all, even if you are a beginner. And i am not saying it wouldn't do anything, ofc it would, everybody has to start from somewhere, but those are very basic numbers, easy to achieve for anybody. And if you would do only this routine, you would quickly reach your limit of how much you can progress with this training routine.
Just to make it clear, i commented on the whole routine that Saitama did as a training routine in real life and from those few exercises that he did, 10km is the most challenging one. And keep in mind he did it every day for 3 years (i think), doing 100 push ups, sit ups, squads etc. each day isn't gonna get you far lol - at some point it would be wayyyy to easy for you and you would need to either increase the amount you do if you want to improve endurance or put extra weight on yourself to get more resistence to build more muscle. Or switch to more difficult exercises.