On the models designed for the US market - maybe. I have checked with 3 cars being produced specifically for Europe: Volvo, Audi and Toyota. While on the majority of videos and instructions there's a special off switch, on those cars it does not exist.
Pretty sure it's mandatory - I seem to recall a considerable educational campaign when they first arrived in Poland regarding passenger front side airbag and child car seats.
I think you are incorrect on this, certainly for Audi but probably Toyota and Volvo as well.
All my European cars had that option including a 2005 diesel Suzuki Jimny and a 2013 Audi A1.
I live here and have rented vehicles across pretty much all brands and have never seen a car where the front passenger airbag can't be turned off. In fact there are ~identical regulatory stickers on the passenger sun shade warning that the passenger airbag needs to be turned off when a rear facing car seat is used in the passenger seat.