Alyx came out 4 years ago, and is recognized as one of the best VR titles of all time. It's a full 15 hour game, so not a tech demo. I'd say that's a hit.
I game at 3440x1440 ultrawide, and upgraded from a 3090 to 4090. 4090 is significantly faster and smoother. And DLSS3 frame interpolation is no joke- in Hogwarts Legacy with every setting cranked up and max ray tracing, turning on DLSS3 jumped me from around 80fps with noticeable 1% low stutters and now pegs it at the 144fps limiter I set in game. Smooth as butter.
Also I mess around with some AI things like stable diffusion, and it's much faster for that as well. As much as I hate the term "future proof", the 4090 is more worth it in that regards, IMO.
Microsoft's Gamepass gives you a discounted price on games, so if you see that something is going to fall out of their subscription catalog you can purchase it for less. It's only like 20% off but it's nice that they offer it.