You can get huge HDDs for about $15~20/TB (US) right now – possibly even better priced if you spend more than the 30 seconds I did looking. You can get up to 30TB in a single disk now if you really want.

I have hundreds of games I’ve bought on GOG over the last decade or so. I have a copy of the offline installers for every single one of them, and they can fit on a single HDD. Literally the first thing I do when I buy a game is download the offline installer so that it’s mine forever.

If you give a shit about preserving the games you bought and don’t do the bare minimum of downloading the offline installer for what you paid for… that’s not a problem with GOG; that’s on you.