Hey Link-Builders, how do you find backlinks?

Hey Link-Builders

Hope you are doing well.

I started working as link builder in an seo agency, and my question to you link builders is how do you get lots of backlinks for your clients beside outreach cause nowadays we know Google "cleaned" a lot of sites and all i see now is Reddit, Quora, Linkedin, BBC, CNN? How can i find good sites, blogs, niche sites...?

Thank you WordPress ...