One of the issues is not every car is the same. My partner had a 1 series M sport whilst I had my 5 series.
As the person who looked after the fleet reported to me i got through a lot of cars (we typically had 3 or 4 manufacturers who would lend us cars, often the press ones after launches).
I drove the 1 series in normal and M sport, and the normal was a better drive by far. The 5 series I found the opposite, the standard suspension made me feel sick, it felt like sea sickness. Ok I had pretty much always had hard type suspension cars, but the standard 5 honestly gave me the same feelings as I had as a kid getting sick in the back of the old mans allegro! Stick on the sports suspension and it was much much nicer.
And I think this is the issue, comparing not just brands, but cars within a range.
There are cars you would say are premium in Toyota, but they are certainly cars far far from it. Some of the marques are basically all premium in target, Audi being one. The whole point of the brand is the premium market, so yeah they use better materials etc, but you do pay for it.
Ford aren't premium but they have premium trim, vignale
You would expect all executive cars to be premium, you wouldnt (nor would people buy) all superminis as premium.
And lets not start conflating engineering reliability with premium