The strongest hard counter to Moira is Roadhog, it’s impossible for a Road to die to Moira 1v1 without her being aided, she simply can’t deal enough damage in the time it takes for his self heal to be used again.
Also to Jacqui, this is an open discussion to help people who find Moira to be annoying to impossible to play against, do not get hostile that someone does not feel the same as you on the topic, if you’re going to do that, please do not post.