Consoles are a significant investment, to only be able to buy content from one source creates monopolies. An equivalent would be if TVs were sold by Netflix or Disney, and only played content purchased from those entities. The second hand game disc market prevented those monopolies from taking prices to stratospheric highs.
I believe this is why digital distribution has seen little push-back on PC, because we have the convenience without the monopolies. Steam is huge, but Epic, Ubisoft, EA, gog.com, and others provide plenty of competition.
If consoles go digital only, from a single source, I think we'll see >$100 games quickly, we'll see subscriptions required to play be much more prevalent, and we'll see the death of consoles within a generation.