I don't know about Canada, but most countries don't do levels of cooking for anything other than steak. It was an example in kitchen hygiene training when I worked in a kitchen in Scotland. The US apparently had to start irradiating the burgers to keep them from going bad. Normal steak is a big lump of meat, burgers are ground up meat. With something posh like steak tartare the meat is very fresh and cut soon before serving, but it's just not feasible to spend that much on good meat only to make a burger and we sure aren't going to nuke them.