If a whole run can be rejected due to not saving at the end because that save verifies the run being single segment. Why is there a rule to capture the whole run that clearly shows its single segment if verified correctly?

Its not a big deal to save at the end Im just confused.

It is a way for you to record your time to avoid the misuse of "Splicing" (when you compile several videos into one) and shows that you finished the game in a single segment, and save the game shows your number of saves;

if 001 appears in "Saves" on the machine it proves that you did it in a single segment;

and this detail is very important in the console versions because it does not have autosplit and many people post runs just showing a short video of the runner saving the game at the end of the game (which in my opinion should no longer be allowed) because it is easy to catch another runner;

in the steam version LRT is used and IGT is still valid, but it does not mean that you can or can not save the game in the last save option;

this detail is still maintained since the leaderboard went through several updates and with old moderators.