physical sales won't go away
I know you're sitting there as a young male with no responsibilities and income and the whole idea of buying physical media seems so lame.
But you're still not the majority. Teens can't have credit cards and a lot adults don't want to deal with downloads (ie makes a shit gift) and even online sales are an annoyance to a lot of people.
Deal with the fact a lot of people like real goods. Given that even vinyl sales have yet to die don't count out physical games yet.
Regrading the death of used sales, yes it'll happen if you eat whatever crap publishers feed you. Otherwise people will fight it