Slight hijack, but this comes down to something I’ve said for years:
There are burgers and there are sliders*. **
Burgers are thick, cooked to order (i.e., rare, med rare, etc), often a “better” quality of meat, may include other things besides meat in the patty. Red Robin has a burger, as do most local burger joints - such as the oddly named Bird’s Aphrodisiac Oyster Shack here in Tallahassee which makes a burger that is a contender for best I’ve ever eaten. Certainly best in town. Damn fine oysters too.
Sliders are thin, often pressed or smashed on the grill, always cooked through, and should be no leaner than 80/20 beef (and beef-only aside from maybe a spice or two). 5 Guys does sliders.
They are both delicious and the food pantheon is big enough for both of them, but comparing them is a little silly. They’re different things.
* I’m using the old definition, not that new-fangled thing where a slider is just a tiny burger.
** There are other things made of (shudder) not beef. These are patties or sandwiches. Not burgers or sliders. There is no such thing as a turkey burger, there are turkey patty sandwiches. 