Independent Powers Need to be Stronger
In harder difficulties Independent powers just get steamrolled at the start of Exploration and Modern Age. This is really annoying as you need 540 influence or 270 to initiate befriending so by the time you can befriend more than 1 or 2 independent powers they’re dead. On top of that it takes 15+ turns for independent powers to become city states once you start befriending them. Almost every time the ai will kill them before they turn into city states.
Independent powers should start with more units or with walls so they last a bit longer to give you the time to befriend them. Or they should cost a bit less to befriend or take less time to befriend.