its not just a 10minute relay race of first passed the finish line
the winner also has to pass a drug test to make sure there is no nasty stuff(bad transactions) inside their body(block)

the first winner with a clean test(transaction list) result is accepted.

everyone then keeps that list(result) and memorialises it. and then the next race begins

a malicious miner at race 2 who wants to edit the results of race 1. has to run race 1 and then do race 2
but by that time malicious miner is at race 2 honest racers are on their 3rd race. so the malicious runner has to run 2x speed to catch up

it costs alot to run 2x the number of systems as the network. so he better be sure he can win and not get caught if he hopes to take the lead and get himself declared the new victor of the last few races and previous victors declared void