Why do you think, that only Earth-like planets can support life? We don't know anything about other systems or galaxies at all. Our knowledge is very minimal in this case.
[Anyway, there must be billions of Earth-like planets in the various galaxies probably.]
To support life, a planet must be of a certain composition and size, including water, not so cold it freezes, not too hot. It must be a certain size or nothing big can live on it (intelligent life on cold Saturn which is so heavy its gravity pulled apart it moon into truck-sized chunks, because the gravity basically kneads anything bigger? No.).
Life needs to be carbon based (due to that atom's special properties) and use water, basically, which only works between say -15 and +120 degrees celsius, if we include really weird microbes in ice and volcanoes.
(If I remember right, chemistry/physics says silicone life forms such as bacteria would be possible, but mating would take 10.000 years or more ...).
The planet needs to be roughly earth-sized ... small planets like Mars lose their athmosphere too quickly, and large planets have a crushing gravity problem for anything that is large and non-flat.
And the planet needs some luck ... Venus might be lovely if not for the rampant greenhouse effect with sulphurous acid clouds and a surface temperature that melts lead.
So let's say we need a ball of rock at or near freezing temperature; mostly liquid, mostly below boiling point.
The "Life zone" around a sun is where a rocky planet would get enough, and not too much, energy.
Most systems are dual stars; now astrophysicists know the laws of gravity very well and simulations say it's unlikely for a dual system to have planets in stable orbit.
Large stars burn very intensely, sending forth fierce amounts of UV and/or gamma radiation, which destroys cells.
(The ozone layer used to protect us from the small amount our sun sends out.)
Life needs time to develop so we can rule out any sun that lives less than, say, 2 billion years for the planets to stabilize enough to support life ... and another 1-2 billion years for life to evolve. If I remember right, that means any sun larger than 3-5 sun masses is likely to go BOOM before intelligent life can evolve.
Small stars like brown dwarfs, hmm: Basically gas planets so huge they fired up nuclear fusion inside, but not a lot ... if I remember right, it's too cold around those. I think we'd need a sun larger than 1/2 solar mass or so.
Again, all "science" arguments quoted from memory off a TV series run by an astrophysicist, so my estimates may be badly wrong in some cases.