- Red dwarfs are by far the most common type of star in the Milky Way, at least in the neighbourhood of the Sun
- Red dwarfs exist for a long time (longer than ten billion years) which gives life a long time to spring into existence (or start via panspermia) and evolve
- Planets in the habitable zone of a red dwarf are tidally locked ("eyeball planets") due to their small distance to the star
So there is very likely to be a huge number of these types of planets with stable conditions over a long period of time.
Flares by the red dwarfs (which are not so rare) could destroy life on these planets
As a layperson, I'm curious how "bad" those flares are. Is it in the realm of possibility that life that develops on these planets could "hide" from these flares when they happen, or evolve defenses against them for when they happen? Or is it more "turn the surface into lava" kinds of events?
You could have life that's 100m deep underwater, or living in protected structures (caves, etc). Life could evolve more protections against UV (e.g. some kind of carapace that the organism resides within).
Maybe the hard part is figuring out a way to use UV-heavy light to generate energy.