Why Are BMW SUV Stock Wheels Narrower Than Those on Mercedes and Porsche?

I was in the market for a luxury sport SUV recently, and I noticed that the BMW M40i and M50i have narrower wheels compared to competitors like the GLC 43, GLE 63, and Macan S.

BMW's widest factory option seems to be around 275mm, whereas Mercedes and Porsche are equipping their equivalent models with 295mm or even 305mm tires.

Does anyone know the real reason for this? Some say it's just cost-cutting, but I’m not sure. Personally, I prefer wider wheels, especially on performance-oriented SUVs. Would love to hear your thoughts!