Assuming you’re using https, your ISP cannot see what pages you visit. It can only see what website you access (IP address).

As someone who hosts my own dns server I can confirm that I can see everything that is accessed but the not the whole url, I can see the base url like if you access YouTube, I’ll see that you pinged YouTube.com, what you received exactly I don’t know but I can tell that you went on YouTube.

I always thought private browsing was just so all the porn content doesn’t stay in search history’s and the address bar doesn’t auto fill fatasshonkeybabes.com if my grandmother sits down to look at her Facebooks.