That’s fair, but he would be able to play the games in the meantime. And since hardware generally gets cheaper as time passes, if he could set aside more than the subscription fee each month to save for his own hardware, he’d be able to game in the meantime. And if he ever had to cancel it, he’d be closer to being able to buy his own hardware than he is today - meaning more time total spent gaming.
It's a fantastic option at this point. I've been a GeForce Now user since 15 or 16 (whenever they launched the ShieldTV beta) and it's.... ok? You can still run it on deck as well of there's any concern.