I can only speak for Whitetail deer harvested in the Midwestern US. In these areas, they primarily eat grass, acorns and wastage from the fields (soybeans, corn, etc.). Also, I butcher my own animals; unscrupulous butchers (e.g. the "We just grind it all into ground meat and jerky") have a tendency to not trim all of the fat and non-meat tissues before freezing their meat. In my case, I have often had people tell me they cannot tell the difference between beef and my ground (15-20% beef fat and venison double-ground). When it comes to the roasts are steaks, the only real difference most people can discern is the meat is a deeper red color. Also, if you insist on having your steaks cooked hotter than medium (above 145°), venison steak is a good choice. The reason being, at these temps and hotter, the steak gets tough and dry more than beef; this is due to it being very lean).

Hopefully that answers some of your questions about it ☺️