I'm in the same boat. My ISP's DNS servers tend to be very slow and often unresponsive. As a result I've used googles (a bad idea, in retrospect) for the last 10 years or so.
> I've used googles (a bad idea, in retrospect) for the last 10 years or so.
That is a reasonable consideration, but Google is very specific about how they use and retain data collected by Google Public DNS. Assuming they are not lying, I don't think it's a significant concern. (Admittedly, their policy is not as good as Cloudflare's "no IP logging" policy.)
TL;DR: Logs with IP addresses are deleted within 48 hours; permanent logs keep city-level location data, but no personally identifiable information. "We don't correlate or combine information from our temporary or permanent logs with any personal information that you have provided Google for other services."
There aren't many ISP DNS servers that aren't garbage in my experience. Most of them don't send NXDOMAIN. Many of them are slower than either Google or Cloudflare despite being theoretically closer.