My gravel bike can apparently handle 650b x 62mm...which is 2.44" tires.
Using a tire that wide has never been something I have given serious thought to...in part because I would need to buy another wheelset too.
700c in 45mm width works fine for me in my area and how I ride. A lot of pavement miles are on my gravel bike too.

If someone gave me a quality 650b wheelset with some quality 2.2" tires to try, yeah I would definitely try em to see how I like the setup.