Russell and Leclerc will never be champions. Norris might win it again
I say this because I think their time is slowly running out and they should be soundly beating their team mates if they were to look like future champions. But their team mates are the WDC main contenders and they're not.
If Hamilton soon closes the gap to Kimi, both Charles and Russell are going to have to accept the 2nd driver role to their team mates and support their WDC challenge, which will definitely change their teams dynamics for the next years.
Also, they are underperforming quite a bit: they are further behind in the standings to their team mates that Norris is to them. And Norris has an inferior car AND one less race start this season, with another race in which he hasn't run FPs
On the other hand, Norris has already proved he is able to beat his team mate, win a WDC and produce great races. Also, McLaren has proven that they are capable of upgrading their cars until they become dominant