In general, you can beat whatever is meta if your more experienced with your champion than people utilizing an unfamiliar meta champion. Also the meta changes very frequently, meaning that its not that worth it to decide mains based on what is meta at the moment.
At the moment, the meta is mainly focused on champions who are good with duskblade (Mainly assasins) and a group of tanks that are a bit overtuned. Karma support can really shut down alot of these champions due to how good her entire kit is at protecting her back-line from these threats, so if you continued maining Karma you would be able to respond fairly well to this meta.
Support can be kind of wonky since your skillful play can be lost on a terrible ADC, but so long as the ADCs are somewhat decently matched you will have chances to prove your mettle over the other support. Even if your adc isn't the best, your utility can aid other allies once the laning phase is over. Also this role is the most common selection for autofill, so occasionally you will be against someone less experienced than you.
There exist alot of good resources for keeping up to date with this kind of stuff, many youtubers (Especially the high elo ones) will straight up tell you whats meta at the moment in their videos, and winrate websites such as champion.gg can give you a grasp of whats popular and succeeding (Keep in mind that win-rate isn't directly correlated to their overall strength, a lot of other factors such as play-rate and player experience can factor in).