They’re absolutely everywhere in Canada, so much so that it’s easy to forget that they’re not used everywhere. As a curiosity for anyone non-Canadian, if you were going to go to the hardware store and get screws to screw together some dimensional lumber (e.g. 2x4s), what kind of drive would you expect to find? I’m not even sure if I could find 3” wood screws here that aren’t Robertson.

Standard would be pozidriv, probably PZ2. You could certainly get torx if you preferred though (or Phillips or flat, if you really hate yourself!) - UK.

They're readily available in the US as well. I've mostly used them with pocket holes.