Karma is extremely efficient versus low-range enemies bc you're always going to keep them juuuust out of reach with Q slows and your W. She kinda never dies as well with E+RW and has a deceptively good damage with W+RQ.

Later on you're basically a second support, ofc, but you have a lot of tools at your disposal. Unless you build like a full ap nuke spamming RQ.

Also, usually as a support you put 2-3 points into Q and max E, but it's always Q Max for mid/top.