Something that makes color icons harder to support is the presence of dark modes and sometimes choice of themes within light mode and dark mode. Where a single set of glyphic icons they can simply be tinted appropriately, but with full color icons you’ll need at minimum a base set for light mode and secondary subset with problematic icons adjusted to work under dark mode. It’s easy to solve from a technical perspective (in CSS there’s media queries, on Apple OSes Xcode has built in variant handling for images) but there’s still the extra overhead of creating the required resources.