[flukus]

> Out of which some 3 billion years had to pass before unicellular forms of life evolved into multicellulars.

We might be a slow developer and poor representative sample in that respect, but without more data it's hard to tell.

> plus, not many planets could provide 3 billion years of "good weather" (or staying habitable) to start with.

I suspect the opposite will be true, red dwarfs are the most common type of star and are stable for trillions of years. Even if the average time it took multi cellular life was 30 or 300 billions years then it might not matter for life evolving there. They do come with some other caveats though: https://en.wikipedia.org/wiki/Red_dwarf#Habitability