McLaren trying to win championships challenge (Impossible)
I think at this point it's clear they don't want to go for the WDC for whatever reason. And with Ferrari not that far behind and them blundering like this again and again, I would not be surprised if they don't win the WCC as well.
And to be a bit sarcastic: I'm sure Lando is happy to have let Oscar pass in Hungary after they told him how important the team is for his chances.
They MUST capitalize as much as possible on any weekend where Max/RB are not strong, such as this one.
In a perfect world, Lando and Oscar would have worked together to defend from Ferrari and secure their 1-2 with Lando at the front. That would have been 17 points to relieve them a bit of this pressure of performing perfectly on all remaining weekends.
Of course we don't know if Charles/Ferrari would have won either way with their strategy. But Oscar gifting Charles a Lap 1 overtake on Lando and both McLarens straining their tyres racing against each other probably didn't hurt Ferrari.
Before today I seriously thought that Lando/McLaren had a chance at WDC, especially with Baku and Singapur still coming up. But as you said, they have shown again and again this season that they can't execute the race weekends necessary for this to happen.