None has ever been tested.

Is a moon really necessary to stabilize the the earth's rotation and the obliquity of the ecliptic? Is hat stability really necessary, or can life adapt to the lack of it?

Can a magnetic field radiation protection be substituted by anything else?

If we are tidally locked to the star will our weather be screwed up, or will the atmosphere freeze/boil away?

Do M dwarfs have too many flares for life to evolve on their planets?

Is plate tectonics a requirement?

Even, is where and when in the galaxy's evolution we're formed make a difference in the chemical composition of the solar nebula?

We don't have any examples to say for sure if any of these things is a game-channger. And we do know life is incrediubly adaptable. Not to mention, look at how much the earth has changed just since life arose here. We've been severely hammered dozens of times, and pulled through OK.

Besides, gas giants can have dozens of satellites, all differnt and each a potential earth.

No, I think the biggest spoiler is our own imagination. We always imagine aliens as being too much like us, terrestial creatures of roughly humanoid configuration, living on a world roughly like our own. I think all you really must have is long term dynamic temperature stability and an orbit that stays in the Habitable Zone most of the time.

Any stable late main sequence subdwarf that can last a few billion years is a suitable prospect. And that is the most common star there is. nd although our world may seem awfully stable for us, but for a subterranean or aquatic creature from a planet orbiting Barnard's star, Earth could be a real hell-hole. Come to think of it, about 90% of our own planet is uninhabitable for hominids without technology and social organization.