I don't understand overtime

This is my first shooter I've played consistently, prior to this I played LoL for the past 12 years, so how fucking forgiving comebacks are frustrate me. I feel robbed when we hold the point to 99% and then the enemy team gets 14 years to contest it. I also don't feel great about winning against an objectively better team because we had an infinite amount of time to contest with 3 support ults at 99%. You should be rewarded for a dominant game and punished for losing.

What is the point of overtime? There is a game clock and a distance measure for a reason. You have X amount of time to accomplish your objective, and if you fail it then that should be it. Tie breakers should also almost never happen.

Side note, why is overtime so God damn inconsistent when nobody is actually on the point? I've seen the meter deplete in 5-8 seconds, and also seen it slow down to a damn crawl.

Team A pushes all 3 checkpoints and had 45 seconds left on the clock. Game should end if team B is pushing towards the 3rd point and hit 44 seconds. Team B accomplished less in the same given amount of time.

Take it in a different context, a runner should get 1st place if they cross the finish line first. They had an objective, and they finished it faster than other competitors. The other competitors had the exact same track. The only difference is they just weren't as good.

Maybe I'm too used to building up leads or getting crushed by them by other games, but you EARN those leads. And it feels incredibly bad to have them mean nothing.