Carmack is still one of the best in the indusry, I've cared way less about QuakeCon since his absence.
His legacy is second to none with what he did pushing to open source early id Tech engines (Doom/Quake). They are kept alive bettter than any games in history. Even now there are still new maps, mods, ray tracing, Vulkan, etc. added for those games for that reason.