And this is the real cost. Sorry Mario Brothers will pretty much always be available as long as Nintendo is around, but obscure games or classics with disputed Copyright will disappear.

Who is out there even trying to stream the old Sierra games? At least they are on GoG, but I know even GoG has tried to track down current copyright holders for old classics and the are plenty of orphan games where after several mergers and divestments, there is some uncertainty, and it's not worth it for any of the potential copyright holders to sort it out and license it, and unfortunately it's not worth it for GoG to publish it to find out if they'll sue GoG.

This is why Abandonware is such an important concept.