I feel like everdrives and a couple of games you're fond of is the way to go. I mean, no one could possibly have an affinity for every Neo title, individually... I have most of my retro stuff sold off and aside from my Turbo Duo which I had to because of financial difficulties at the time I don't really miss it. I've kept a few games that mean something to me or have a nostalgic feeling for, because for the most part unless you want to play them they don't really mean much beyond their shelf space dimensions and a +1 in the totals.
For the games I don't own, it used to be enough to just fire up an emulator and play them, but it never felt right (aka the MUH ACCURACY hoarder's excuse). An everdrive pulls that out of the equation entirely and makes adding games to an already big collection nowadays a moot point, after all the whole point of the cartridges/discs is to play the games inside them, always was and always will be (exceptions apply to "preservationist" wannabes?). There are plenty of people who care about old video games, but also couldn't care less about old Chinese plastique circlejerking.
tl;dr: everdrives available = don't buy overpriced games in 2020, dummy. And maybe sell a few of your own.