Audi Quattro is not a rear biased AWD, it is permanent rear biased AWD (40:60)
There is a new front based version of Quattro that is more similar to VW 4Motion but that is not available in US A4 or S4...A3 and S3 have transversly mounted engines and have the third version of Quattro which is similar to Giulia except that it is FWD first before lack of traction kicks in power to rear
Biggest Audi’s problem is balance, engine is mounted entirely in front of front axle, that is even more problematic in S4 with heavier engine....it has consequentially lots more space and much larger trunk plus it is in B9 iteration about 4 inches longer than Giulia
It is perfect hwy cruiser and has superb tech if that is what floats ones boat but will push and understeer all day and twice on sunday, it is do much heavier kn front that has much narrower track in the back but it stil understeers at slightest corner
Shortly, A4 is a sales rep compromise car,Giulia is a compromise that makes for fantastic fun on curvy roads
Audi are not designed for driving fun. They are heavier, They are not pointy, they understeer for the exact reason you mention above. In simple layman terms they put safety first.
They are very well appointed just like a Coach purses and they have amazing tech. I had a few A4s and A6s so I speck from "some" experience.
These days I'd buy an Audi for my wife so that she can safely take kids to places but that is it. For myself I want a Giulia for a family car transporter and one with a badge.
Life is too short to compromise.