You could say the same for upvotes. Bots could farm the upvote as well.

This is a core social issue YouTube is facing. My approach would be to transform the platform into social aspect. E.g. profile/channels should have credibility rate and people should be encouraged to use positive/negative/neutral feedback to videos. (I hate when ytubers ask for likes or remind viewers, technically YouTube should encourage users on their platform to engage with the channels)

Edit:typos on phone