I don't know where this myth comes from. Russell is consistently faster than Latifi on a Sunday, as much as anyone else on the grid except perhaps Max over Pérez or Mick over Mazepin, and has beaten him in almost every race. It's not the dramatic difference seen on a Saturday but with the constant need for tyre management and fuel management it's surely unreasonable to expect otherwise.
The top drivers excel when all factors are taken into consideration. Hamilton's advantage over Bottas and Rosberg in race trim, same with Vettel over Webber, Alonso over Massa, Button over Barrichello. It's a part of being a top F1 driver, and Russell will need to show he can do it as well as one of the best in the same machinery if he's to beat him.
I'm not for a minute suggesting Russell is worse than Latifi in race trim - that would be ridiculous, but Latifi isn't far off at all, and has been quicker in some races.
Like I said, I don't know who that's on more - is Russell that good at qualifying, is Latifi that poor? Is Russell just not as good in the race or is Latifi genuinely closer? In reality it's probably somewhere in the middle.
My point being, it's not a foregone conclusion that he's a driver complete enough to compete with the likes of Hamilton over a full season. It's probably going to be bloody good fun finding out though!
Bottas was not catching quickly at any point. The only point he was even a little faster was when he was on tyres 4 laps younger.
He halved the gap from 8 seconds to 4 in 10 laps. On a track with effectively 6 corners. I doubt he would have had the pace to pass him when he got there (this is Bottas), but he would have caught him well before the end were it not for those safety cars.