Volcanic eruptions come in many sizes and “flavors”.
There are the basic, almost harmless lava flows like in Hawaii, the small rock-throwers, the pyroclastic flows, and then there are the really big ones; on top of all eruptions, in terms of strength, are the so-called supervolcano eruptions, large enough to change life as we know it and potentially return humanity to a pre-civilization state. Needless to say, we’d want to know as much as possible about these eruptions.
Thankfully, they happen quite rarely. A 2014 study estimated that such eruptions (which throw over 1,000 gigatons of material) happen once every 45,000 to once every 714,000 years. There’s no fixed cyclicity and there’s an inherent variability of such estimates, but even at the lower end, that’s not a panic-inducing figure.