PCs aren't that upgradable. Short term, of course they are, memory, GPU, storage. But on the timescale of console generations (5-7 years) absolutely not. A commodity PC that is half a decade old can only sensibly be upgraded by replacing it. You might get 10 years out of a really well made and specced PC by upgrading it along the way, but that would have cost much more than a console to buy in the first place, let alone the subsequent upgrades.