All I see in general home maintenance stores is philips/pozidriv. Torx is used in laptops/mobiles and I haven't seen Robertson at all.
Hex drives are popular also, mostly for furniture/Ikea.
(Poland)
I primarily keep stock of their 'cabinet' screws which have a washer head useful for mounting all sorts of things and their multi-purpose framing screws. I'll buy their trim screws as needed.
They are excellent fasteners and they're readily stocked in Home Depot near me, which is a big positive.
They are still relatively rare in city stores that target the general consumer, but they are readily available in larger suburban/rural stores. However, even in these, small boxes are usually only available in Pozidriv, but bigger boxes are often available in both Pozidriv and Torx, the latter being a bit more expensive.
Never seen a Robertson screw there, however.
Square has never been a thing in Europe.
I've never seen Robertson screw in a Polish store.