Karma's R and root are a joke compared to the peel and offensive buffs of Janna
It's honstly kind of disgusting, not that Janna is allowed to be so strong since literally forever, but that she's allowed to do the job of other enchanters better while also having ridiculous peel
max E value: 170 + 50% AP
Other benefit: 60% Movespeed buff for 1.5s
max E value: 210 +70% AP
Other benefit: 40 +10% AP BONUS AD for as long as the shield holds
Okay, so that's just the shield. Some champions should have better skills than others that do similar things, fair enough. Afterall, Karma has her ult shield as well!
About that.
RE max rank bonus shield: 210 +60% AP
(This is a shield, and thus falls off compared to an actual heal)
R max full heal: 600 +150% AP
Holding her R for just one second grants more health, permanently, than Karma's.
Oh but Karma's ult is on such a low cooldown, so of course it's going to have a weaker effect. That's fine, except in a fight, you're getting exactly one Janna ult and one Karma ult off, so the effect is just having a minimal impact.
And then there's Janna's R also acting as a free peel when snapcast, as well as the other hard CC on both champions:
Max rank W: after standing within harm's way waiting for the grass to grow for 1.5 seconds, the enemy is rooted for 2 seconds (an impressive 3.75 if you forgo her RE)
snapcast rank 1 Q: Instant AoE knockup for 0.5 seconds (Increased to 1.25 if enemies are dumb enough to be hit by it charged)
And their soft CC
Max rank Q: A skillshot that slows for 25%, increased to an AoE 50% slow with R, both for 1.5 seconds
Max rank W: 40% + 6% AP point and click slow that lasts 2 seconds
It's just absurd that Janna is allowed to be better than every other enchanter not just in her protective and healing spells, but also have the disengage power of some of the strongest Wardens in the game, on top of buffing the ADCs attack power by 60+.
If Janna is going to be allowed to be the way she is, revert the shield nerfs on Karma and give her slow a significant boost in potency. She's been sitting as a bottom tier support, midlaner, and recently toplaner, for far too long while nonsense like Janna are allowed to do everything she does better and then do more on top of that.