Google

https://www.google.com/search?q=keyword+cannibalism or https://www.google.com/search?q=keyword+cannibalization make me think it's not good.

It's up to you to agree or not.

Why is keyword cannibalism bad for SEO? If you cannibalize your own keywords, you're competing with yourself for ranking in Google. As a result, they'll all probably both rank lower. Therefore our SEO analysis will give a red bullet whenever you optimize a post for a focus keyword you've used before.