They are technically correct in that it’s the developers fault that they tied themselves to a proprietary game engine.
In the other hand Godot was nowhere near mature when the slay the spire devs most likely started development. They would be dumb if they used unity for their next game 🤷
Your comparison between phones and VR/AR is reasonable but a bit different as when windows phones were discontinued, Microsoft had pretty much lost the phone os race. Also the windows phones sucked, I’ve used them…
IMO microsoft gave vr/ar a fair chance. They might have been early, but if we are eg. a full decade off must buy VR, then it might not be worth waiting.