The issue is that a proper gemling isnt cheap and heavily favors 3 items: 5attri/10res Moriors, Ingenuity and Melting Maelstrom.
All 3 combined are like 70 div+ (cheap for some ppl, very hard to get for others) but once you get them with the other stuff (like budget stat rings & amu, Howa, Atziri with spirit if amu doesnt have any, budget boots, 2x pillar) you basically can't die except for few cases like simulacrum or Arbiter (duh).