There's a night-and-day difference between 'doing their best' and actually succeeding.
More and more of our culture is oozing into some kind of creepy politically-correct weakness, where it's all about 'how hard you tried', where winning becomes irrelevant to what's most important.
That's just false. Life on earth has never ever worked that way.
You lose you die.
Chael's dad may have been old-school like that, honoring the gritty brutal truth of the way of the real world, and there'd be nothing wrong with that. That's the mentality that breeds winners.
If that's the case, Chael may honor it, and he may rightfully feel like a failure/loser by that metric. Sure he did his best, and that's absolutely something very important, but in the greater 'hierarchy' of what's important, there's no way you can supplant success/winning with 'tried my best'.
It's a pathological values-hierarchy that flips the script and makes effort more important than results. That's the 'everybody gets a gold star' nonsense that is causing more and more people in the western world to become fundamentally weak.
You'll never hear that kind of weak/feminine shit from someone like Khabib or his dad.