There are exceptions, I still have several physical copies of Fallout 1 and 2 (including the original boxes from the 90s) and I also have them on GOG.
The shameful business model that they are putting forward these days is releasing a better version of an existing game to cash in on users who've been playing right from the start (it happened with Sleeping Dogs, Deus Ex HR, Dark Souls 2, State of Decay, the Metro series).
It's like Steam taking a 30% cut when it's sometimes possible to find a better price if you're willing to buy a physical copy at the shop around the corner.
Some things are only worth getting on sales and that's another point in favour of computers. Console games are really overpriced. I guess it's easier to rent or trade in games for consoles but even on full priced new releases the difference can be rather important.
"Growing old is inevitable but growing up is optional."