Google : number of results

Hello !

A former friend told me that a score of 0 (KD) on a keyword with the Ahrefs tool was not enough to rank on Google.

He advised me to type the query into Google, and observe the number of results.

According to him, if the number of results is less than 1,000,000, then the keyword is not competitive at all, and it is easy to position on it.

It seems to work since barely 3 months later, I start to stand out on these keywords.

My question is : from when can I "increase" this limit by 1,000,000?

I imagine my blog is gaining more and more power, so how do I know when to broaden my keyword research?

Thank you all