You can use Jorgan for a pretty long time, but by the time you hit the 40's your dps will not have scaled up with the higher lvl mobs hp resulting in much longer fights, which means the incoming dmg will be much more.
For comparison, my lvl 46 vanguard, in level appropriate gear does less damage than my combat medic commando did in the mid 20's, let alone if she was gunnery spec. If you have only played a vanguard, you will be amazed by the damage output of some classes like commando or gunslinger (but with less survivability\staying power, gunslinger especially)
The time it takes to kill multiple 10,000-15,000hp strongs, or a strong and 3-4 6,500hp normals will take a huge chunk off your hp bar and you will have to use recharge and reload after every single fight, vs staying at 100%hp with elara.
With Yuun, i can -barely- kill 2 strongs with supporting normals, and a pair of elites would be impossible if they couldn't be kited. With Elara, I would never drop under 95%hp and can simply go from group to group dropping as much AoE as the cooldowns allow, making for both a faster, and much safer experience.
The amount of content that would simply be impossible without Elara is quite large if you are a completionist and don't want to go back after being over-leveled. I have soloed all 2+ heroics with her, and several 4+ heroics. Champions are trivial with her, but impossible without.