No, they actually aren't. The heat flow that powers Yellowstone is roughly similar to the one that powers Mauna Loa.
The difference is that Hawaii hotspot is constantly erupting, and has produced roughly 6000km^3 of new rock in the past 650 kyears, which is how long it is from a proper Yellowstone supereruption, while the Yellowstone hot spot just builds and builds material and heat, until it finally all goes off at once. This is what's believed to be the difference between supervolcanoes and normal ones.
There has been volcanism on a much larger scale in the past (see: large igneous province), but they aren't really volcanoes in the sense we understand them, and are not related to supervolcanoes.
The difference is that Hawaii hotspot is constantly erupting, and has produced roughly 6000km^3 of new rock in the past 650 kyears, which is how long it is from a proper Yellowstone supereruption, while the Yellowstone hot spot just builds and builds material and heat, until it finally all goes off at once. This is what's believed to be the difference between supervolcanoes and normal ones.
There has been volcanism on a much larger scale in the past (see: large igneous province), but they aren't really volcanoes in the sense we understand them, and are not related to supervolcanoes.