Even something as catastrophic as the eruption of Mount St. Helens was, in the end, a life-giving event.
You are in good company if you are as skeptical about these claims as I am myself.
Flowering plants or angiosperms appear abruptly in the fossil record of the Lower Cretaceous (about 130 million years ago).
Don’t walk on the grass, that “often undervalued” form of life, without looking down. It’s amazing down there.
All orders and families of the angiosperms appear abruptly in the fossil record (the same for most lower systematic categories).