Anyway, you're comparing mainline cars to performance variants. .
My point was that you can get 6 pot petrol cars in high end 'mainline' models with BMW. Granted these come with M-Packages/badges but aren't true M-performance models. But Merc has moved the 6 pot petrol to the AMG 43 badge and Audi keeps the 5-8 pot models in the S/RS models. Almost everything else is a 4cl or diesel.
BMW does have a lot of models but the others seem to be following suit. Audi says there will be more S/RS models and have just added the Q2 with the Q8 on the horizon. Merc brought the AMG 43 series and are watering down the SUV line. People's priorities/tastes in cars are changing hence manufactures have to meet them halfway to maintain sales.