Back up phone my Nokia Windows phone,
Must have an Original Nokia with me it's a long time habit Twenty years, they just keep working and can fit new battery in seconds. But the Pixel is excellent to use and probably the best Android phone as Google intended, tried a Samsung phone a while back never again.
I LOVED my Windows Phone Nokia ICON! I was really hoping that Microsoft would advance their software, rather than work off Android for their new phones, but that didn't happen. Bummer! I have been using a Pixel 2, which I really like, but don't want to purchase the new Windows Phone because it's so expensive, and not using Microsoft exclusive software. Maybe 3 or 4 years from now it will be compelling ... but not now. I'll purchase the Pixel 5 for now.
I have a Nexus 5X lying around as an emergency backup. The Pixel 3a would make for a great backup, if you need to buy another phone.
My "emotional support" backup phone is my motorola razr v3. I can angrily snap it shut when I hang up on someone on my Pixel.