The user experience of GrapheneOS is basically the same as vanilla Android, except that you have more control (you can uninstall google apps, for example), but at the cost of a small minority of apps (banking ones, for example) not working (out of the box, sometimes at all). My banking app works, and a quick google search will tell you if yours does too. If your old pixel is not too old (4 is no longer supported, 8 definitely is, not sure abt in between), you should give it a go. I think you’ll see it’s not as big of a step as you maybe currently imagine.