To all the people who successfully blog post for backlinks. How many people do you reach out to and how many respond on average?

I was going through ahrefs free training. They said reach out to an average of 20 different websites to get 1 guest blogger. I know each industry is different but what's your strategy for doing so and how successful are you and where do you find your guests? Ive been building lists off of social media and Google so far and writing blogs with low competitive keywords with high search volume