Being from Europe (Sweden) I can't remember having ever seen a square drive screw. Torx is slowly becoming the standard here.
We get some Simpsons stuff in Europe (like nail plates and beam hangers) but I don’t think the screws are sold in Europe. If they were I don’t think it would be very easy to introduce a square bit screw in s as market where they are unknown.
And obviously, not much uses any imperial naming. I think this is regionally produced because e.g a beam hanger for 45mm timber has to be pretty close to 45mm and a 2” won’t do.
Simpson makes very large diameter, 4" stainless steel screws that I rather like:
#12 x 4", model number is S12400DBB
... those are 306 stainless but if you want 316 you would get T12400DBB.
IF we use screw fasteners in framing, we typically use GRK 3-1/8"-#10 but once in a while we just want something beefier and those simpson 4"-#12 are fantastic ...
... and they are square drive.