Make the "Resolve" Tree Viable for Top and Jungle, Not Just Support
As the name implies, the "resolve" tree should be about endurance or perseverance; it shouldn't be outshined in this regard by conqueror, but too often it is.
If you build one or two tank items and have conqueror on a decent number of champions (like Yi, Garen, or Jax), you are able to survive better than a full tank item, "resolve" tree user. The "resolve" tree is so underpowered in terms of survivability that supposedly "tanky" champions use the Precision tree way more often, e.g. Mundo, Volibear, and Garen.
The flaw comes from the first two rows. They pigeonhole "resolve" tree users into teamfight tanks or splitpushers.
Aftershock doesn't provide enough defense for a 1v1 fight that lasts longer than a few seconds, and grasp of the undying is overshadowed by conqueror in terms of survivability, making the "undying" part a misnomer. Guardian is only... okay? and that's only if you are with a teammate constantly, so supports, NOT junglers or top laners.
As for the second row of the "resolve" tree, most champions can't benefit from shield bash. Font of life only benefits allies, and demolish is only good in terms of pushing. Literally none of these help survivability for the vast majority of champions.
If you want to have a "support" tree, cool, ADD ONE. Don't gimp Jungle and Top choices by co-opting the only available "tank" tree.

takes Aftershock as well, but you have to sweat in order to make plays. Half the time
, and his win rate/play rate is pitiful.