Maybe this is silly of me, but maybe gaming would enjoy an era of hardware upgrades being rather unviable so the focus turns to optimization and aesthetic.
A retraction from the gaming market wouldn't necessarily mean they'd still even produce the current crop of products. I could (and I would argue would) involve a complete shuttering of the GeForce brand, halting current production. On the assumption that Intel and AMD would follow, that wouldn't be an end of upgrades, but an end to the market.
It’s not silly. games use far more hardware than they really need. It also pushes out release dates of aggressive console schedules like ps6 because even if it’s a massive upgrade and you have IP locked into your console, no one is going to pay $4000 to play a game like wolverine.
It will be interesting times but I don't think anyone will enjoy a plateau because it's expensive. Even replacing existing hardware is expensive now. Hardly enjoyabe.