iNouda

I find it really annoying when I spend so much time/effort crushing them with either military or culture and they just give up their stuff to someone else.

It happened to me too. Literally the only time I can win is if I use 15-20 Legions and even then I lose half to a 5 legion defended world when I have max invasion tech and using the special invasion things to soften the planet up. It's getting fucking ridiculous because it takes forever to revive the legions I've lost to one measly planet when I have massive fleets orbiting each enemy planet and crushing every attempt they have to rebuild any sort of fleet. It's taking literal hours to grind