I am on s9 and s11 but speaking about s9 where I am more competitive (my main acct). If I jump into challenger even an hour before rewards time ill just be knocked out. And anyway I have 5 month old plus toddler plus business plus sick parent, not to mention other things, so it's very rare to be able to do it. Sure doing a fight only takes a min but rewards fights must be perfectly timed and that just doesn't happen often with young kids around.
Anyway for the gajillienth time the main point is that a fair solution is to give every player in the world the same opportunities and difficulties throughout the year. I'm certainly not asking the game to cater to me personally. I'm just asking for it to be fair to all by rotating the clock periodically.