Wikipedia:

"threat

If our universe is in a false vacuum state rather than a true vacuum state, then the decay from the less stable false vacuum to the more stable true vacuum (called false vacuum decay) could have dramatic consequences.[5][6] The effects could range from complete cessation of existing fundamental forces, elementary particles and structures comprising them, to subtle change in some cosmological parameters, mostly depending on the potential difference between true and false vacuum. Some false vacuum decay scenarios are compatible with the survival of structures like galaxies, stars,[7][8] and even biological life,[9] while others involve the full destruction of baryonic matter[10] or even immediate gravitational collapse of the universe.[11] In this more extreme case, the likelihood of a "bubble" forming is very low (i.e. false vacuum decay may be impossible).[12] "

Also, of course there's a Kurzesagt