Meaning isn't binary and "system-search" could mean many different subtly different things depending on the application and the context. Often the choice of icon requires context that factors in the specific iconography.
For example, what happens when there's system searching element that needs to be in visual proximity to a magnification, zooming or loupe-inspection element? It's impossible to know if an icon theme is going to maintain consistency and/or disambiguity with the default theme.
> Meaning isn't binary and "system-search" could mean many different subtly different things depending on the application and the context.
Actually, "system-search" is always "The icon used for the “Search” item in the desktop's panel application.".[1] Admittedly that makes it a bad example because an application generally doesn't need this icon.
> For example, what happens when there's system searching element that needs to be in visual proximity to a magnification, zooming or loupe-inspection element?
Hopefully, the application uses the standard icons. The user might have difficulties distinguishing idiosyncratic, unfamiliar icons.
For example, what happens when there's system searching element that needs to be in visual proximity to a magnification, zooming or loupe-inspection element? It's impossible to know if an icon theme is going to maintain consistency and/or disambiguity with the default theme.