"No planet B." Which may be one explanation of the Fermi paradox. " Why don't we see vast numbers of advanced alien races, all across the universe, if life is common and inevitable ? " Could be, because, all technological cultures destroy their home, and themselves, quite quickly.

It could be slow in terms of human life times. Or it could be, that there is a doomsday technology waiting discovery. Perhaps there is, (say) an advanced jelly bean maker, just waiting to be discovered, but a soon as you press the start button, the whole planet goes up in smoke. Sooner or later, all civilizations discover the jelly bean maker. And pop ! They are gone.

Destroying our planet?

You exaggerate.

There is no Plan B. There won't be. Sorry.