Space is hostile to life. After 4 billion years, life cannot propagate to nearest planet. We are lucky that life on our planet is not erased yet, but it will be

Space is hostile to life. After 4 billion years, life cannot propagate to nearest planet. We are lucky that life on our planet is not erased yet, but it will be erased in about 2-4 billion years, when oceans will boil, then when core will freeze, then when Sun will consume the planet. Out of 6-8 billion years, 3 billion years was spent in single-cell form of life. We are extremely lucky. We can calculate how many stars are formed after a supernova event, how many Earth-size planets in the habitable zone are survived after collision of two objects of comparable size, how many of them survived with ocean and large moon, to make large tidal waves (I suspect that first cells were formed as greasy puddles, then partially dried out, which created a membrane), then how many of them were far enough from a supernova or not erased by it own star in 4 billion years at least. I suspect, that final number will be much less that 200 sextillion, because, to avoid a supernova, a star must be formed in a less dense region.