I've been playing fps/rts/rpg games through GeForce Now on a MacBook M1 and so far there's few obvious drawbacks - good internet required, slight input lag which can be annoying for some FPS games sure, and not all games are available yet - but for those who only play a few games regularly, it's also much better than running the game on an i3/i5 Windows laptop.
Every attempt so far has failed, spectacularly. What is promising about that?
After thirty years of desktop gaming PCs, I sold mine and just use GFN now. It's completely silent (no fan), minor lag (only matters for competitive shooters), and much cheaper than maintaining a high end gaming rig.
Compared to consoles, it has much better graphics, can be played anywhere where you have good internet, supports mouse/keyboard, ultrawide, 120Hz, etc.
Compared to the Stream Deck, it has much better graphics, much longer battery life (it's just streaming video, not rendering on device), and no heat or fan noise. I also sold my Steam Deck because GFN plus a streaming portable (Logitech gCloud) was way more ergonomic.
Did cloud streaming really fail, or is it just a niche? It's come a long way since OnLive. Stadia was a royal fuckup but not because of its technology; Google just had no idea how PC gaming culture works. Their competitors are still around and doing fine, if not making billions.
It is still a very useful tech that I use daily.