I can't help but roll my eyes when people claim that within the next 10-15 years all gaming will be digital-only, possibly even streaming. Every time somebody proclaims the impending demise of physical media reality comes and smacks them down. Not even the music industry has forced everyone to start streaming or buying mp3 players, and they've been impacted the most of any entertainment sector by digital media. Yet people have been proclaiming for years that, any day now, all the CD presses would shut down. Print books and Blu-ray were supposed to be dead already as well, yet they're still here with no signs of dying any time soon. And sure, the PC part of the gaming market has voluntarily shifted to digital, but that's because A) it's an open platform, which allows for competing digital stores and thus better service and lower prices, and B) the second-hand software market never had a historical presence or even a legal basis.
Consoles are very different beasts from PCs, though, as is their respective markets. In 2014 (the most recent data I have for this; it came from a DFC Intelligence report from last year), total U.S. unit sales for retail-release console titles had physical outselling digital roughly 18-to-1 not including bundled software. Even for first-week/first-month sales of major titles, evidence suggests that the vast majority of sales for most titles are physical copies. Console gamers overwhelmingly prefer physical copies. And that's because the second-hand market, protected by the first-sale doctrine, has been a huge part of the console market for over 30 years.
Furthermore, consoles are closed platforms. For consoles to go all-digital, not only would it have to be forced (something no other sector of the entertainment industry has done before), but a console owner would be locked into that platform's one exclusive digital storefront. There's no competition and thus no incentive to reduce prices. You buy a hypothetical digital-only PS5, and you're going to have to buy games exclusively from the PSN store. Period. They would fully control every aspect of the distribution channel. I fail to see how anything good could come out this situation.
And all of this is to say nothing about the myriad other issues of digital distribution and mandatory internet connections, and I don't have time to get into those right now (I have to leave soon).
The console market just isn't ready for digital-only, and it might never be. Maybe once us crusty old Gen X-ers are all dead or in retirement homes, but probably not before then.