some timing-sensitive games such as Clair Obscur (parry) or I Am Your Beast (movement)? sure, they depend on low latency. that said, GeForce Now is, sadly, pretty good nowadays. enough to play a moderately fast paced game such as DEATHLOOP. Ukraine, streaming from Germany. 5 GHz is basically required, but in slower-paced games, on a phone, with 720p streaming, you can get by with 4G.
even games are not really a moat for owning hardware - next Gears with its timing-sensitive reloading mechanic can just get adapted for cloud.
if cloud gaming gets another hype wave for one reason or another, this time I am pretty sure they will lock in a much bigger user base. me personally? still committed to owning my hardware, but I can totally imagine my mother playing some RTS on a GeForce Now-connected tablet and having zero complaints.
Clair Obscur was perfectly playable for me through GeForce Now, for what it is worth, even when hitting parry timing. (N = 1, but a datum nonetheless)
it is possible to adapt to input/network lag, sure. I played Doom 3 at 10-15 FPS in 640x480 and Warcraft 3 with 300ms latency, and I enjoyed it at the time, but I don't think I could endure such underwhelming experiences after many years of much better ones.
honestly I'd still throw a penny for at least a day pass if I'm e.g. traveling. getting that Duollistes or Locust fix on a train looks irresistible