That'll probably take a long time. CD players don't get outdated, and boomers don't know how to add digital music to their playlist.
I don't know how to find anything anymore in my libraries of digital games, it's a mess: Steam, Gog, Origin, MS store, Humble bundles, PSN library, standalone digital games. I can find any physical game around the house in 10 seconds...
Physical editions will continue to exist but move more towards special editions bringing back the extras. The question is will game stores be able to survive much longer and where am I going to get my console and games from when they disappear. I guess games are fine to order online but consoles :/