Linux users don't need much GPU performance to run OpenOffice and Firefox as neither did the Windows users who used their work PCs to fill in TPS reports in Excel.
They do for games, which now that Proton works so well are actually a reality.
Yeah but we're not talking about gamers, which are minority of worldwide PC users both Windows and Linux. Most PC uses don't revolve around demanding games but productivity tasks, for which Intel graphic are more than enough. You don't need to get an extra Radeon GPU to watch Youtube and file your taxes.