The Most Habitable Alien Planets Might Be 'Super-Earths'
thedailybeast.com
thedailybeast.com
Maybe 2x to 10x more massive rocky planets are more hospitable for life, but...
It's difficult to make flying vehicles on earth - we had to develop an industrial culture to fly. Rockets to orbit are even harder, on a 1x Earth, we can just barely get stuff into orbit.
On a 2x Earth, flying and rockets might be theoretical, but practically impossible. On a 10x Earth, flight of any kind is probably impossible. Such the habitable planets might have non-flying civilizations only.