The most “Earth like” planet ever discovered is almost exactly the same size and mass as Earth and orbits an identical star at almost the same orbit.
It is called Venus.
I suspect that most “Earth like” exoplanets are far more Venus like.
Hard to say really. We’ve just barely scratched the surface of what we can find. Most of the rocky planets we’ve found are close to their stars where its easiest to find them. Most of those were found by Kepler looking in one very small area of the sky.
If someone were looking for earth using the transiting method, they would have to catch the earth passing in front of the sun then wait 365 days to see it again.
Personally I’ve never liked the term “Earthlike” anyway. It convinces people who don’t follow such things that scientists have literally found a planet like ours. By that standard Mercury, Venus, and Mars are all “earthlike”. Even Saturn’s moon Titan is often described as earthlike but I think I’ll pass on the vacation there.
A side note on habitable zones. People often assume the earth sits nicely in the dead center of the habitable zone around our sun. The reality is that Earth orbits in the inner 5% of the habitable zone with Mars orbiting in the outer 5 or 10 percent.
depends on the star and the orbit of the planet. As the science is refined, we will get better understanding of extrasolar planets atmosphere.