How is the halo product of a range the "sweet spot"?
I think nVidia are extremely exposed on this front. The RX 7900XTX is also 24GB and under half the price (In UK at least - £800 vs £1,700 for the 4090). It's difficult to get a performance comparison on compute tasks, but I think it's around 70-80% of the 4090 given what I can find. Even a 3090, if you can find one, is £1,500.
The software isn't as stable on AMD hardware, but it does work. I'm running a RX7600 - 8GB myself, and happily doing SDXL. The main problem is that exhausting VRAM causes instability. Exceed it by a lot, and everything is handled fine, but if it's marginal... problems ensue.
The AMD engineers are actively making the experience better, and it may not be long before it's a practical alternative. If/When that happens nVidia will need to slash their prices to sell anything in this sphere, which I can't really see themselves doing.