On what terms? Sure many trees, plants, animals, and humans will die in a super volcano eruption. But the resulting ash will help enrich the soil for a decent fraction of the entire country. There will be a huge carbon sink as entire forests are buried in ash, soil will receive additional minerals, and a light loamy soil will result. California for instance has excellent soil (class A good enough for even more challenging crops like strawberries) because of a large previous eruption.
So sure in the short term (years) no eruption is good. But in the long term there will be poorer soil, or a huge amount of energy/chemicals consumed to keep the soil usable.
It's far from clear that it's better for the ecosystem to stop a volcano (or supervolcano). What's next stopping earthquakes? Keep plates from moving? Stopping erosion? Preventing rivers from migrating?
Mucking with nature to prevent the natural cycle of life has gone pretty poorly so far. Floods are getting worse, rivers are moving faster, coastal cities are losing their marshes, cities on rivers are at a higher risk than ever of flooding.
Check out the updates on Mt Saint Helens area in the post eruption documentary. It's quite vibrant and recovered much faster than scientist expected.