also not sure a lot of people would agree Russell's racing better overall (I agree he's proving to be much stronger in coping with what he gets, whereas his teammate always comes off as a crybaby, but I can't really tell about prowess or if both were at the top of every race how it'd pan out), or that how he feels about himself has anything to do with Hamilton's choice.
There are a few things in place that results with this and none of them could give us the exact reason which one is better and which one is worse. I mean Hamilton gets all the new tests and updates, which means that sometimes he has the better car but sometimes he has a terrible car, and we all know Russell has raced with a lot worse cars so far, whereas it has been over a decade since Hamilton ever driven a car that wasn't good.
We also have the fact that Hamilton just lost a great teammate for him who would have left to give him space, and instead got a driver who is trying to beat him, whereas Russell had to fight for any points he could get.
All these combined results with Russell being better on standings for now. Doesn't make one or the other better. Sure, Hamilton had a better career of course, and Russell can't beat that, but Hamilton is older now, so we are comparing today's Hamilton vs today's Russell.