2019 Xcellence Lux Ateca here, we didn’t have an option either. Which is stupid, considering the rest of europe gets an optional beats sound system for it. Though.. For what it is, it doesn’t sound horrible. Certainly nothing for an audiophile, but serviceable.
Whether or not we go for an optional sound system will depend on availability (as mentioned, none on the Ateca), on the stock sound system of the car (Mercedes everything above and including Premium trim has a 225W sound system) and price (Tiguan Elegance, £1000 for the sound system).
I can say that if we had the £600 option for a beats sound system in the Ateca, we would’ve taken it.
Prior: SEAT Ateca Xcellence Lux 1.5 TSI DSG MY19, VW Golf GTE PHEV DSG MY23
Current: Hyundai Ioniq 6 Ultimate
Next: we'll see what's available in 2028.