That's probably great for bolognese or tartare (to name a couple of random examples), but use that for a burger and it would be horribly dry (unless you cooked it rare/medium rare)

Although I'm sure it's possible to make a plant based burger that doesn't need 20% fat by tweaking other stuff that you can't change with ground beef. (I've had potato/sweet potato patties that were great and basically fat free, but obviously not much like actual meat)

Yes, what you call minced beef is called ground beef in America. Not to be confused with mincemeat, though, fellow Americans! I was very confused the first time I had that in the UK.

For the record, Italians wouldn't use anything less than 20% for their ragu. Not that this has much to do with "spaghetti bolognese" I suppose.