Rapha has 2 offerings for cargo bibs and I think the side pockets are decent size. Cuore also has the Pioneer bib which I bought when my club offered them last year. I use them all the time for road and gravel. I think the nice thing about the cargo bibs is they are just regular bibs if you don’t want to use the pockets.
Cuore sells the Pioneer bib in their retail store but I think it is only offered in the camo print.