Welcome to the forum. I have not seen a poll for which custom ROMs do you use on this forum but I would guess that CalyxOS and GrapheneOS would split 80% and the rest would be the 20%.
Installing a custom ROM is a task, but setting it up the way you like it is a bit more work that takes time.
My suggestion is to consider your expectations or requirements. If either Calyx or GraphenOS will work. Try them both.
LineageOS and variants work on older devices that are fun to learn with setting up. If you have access to another device you can try things that fail on the Pixel on the older device to troubleshoot.