[greyskull]

I've never used Comcast's/Xfinity's own hardware. Always bought my own modem and router, which has generally worked out well, outside of when I'm (rarely) having quirky service issues and can't easily prove that it's not my hardware.

If you don't want to do that and keep their gateway, I'd expect you can run pi-hole anyway, and if you're not getting the behavior you want (e.g., the gateway seems to be intercepting dns or something), you can try DNS-over-HTTPS.

[gorjusborg]

I have spectrum, but same in principal here. Having familiarity with hardware I like is why I opt to provide my own modem and router. If anyone is considering going that route, I've had really good luck with ubiquiti networks unifi line. Really great quality for what you pay.