Intel's foundry costs are probably competitive with nvidia too - nvidia has too much opportunity cost if nothing else.
While it doesn't quite compete at performance and power consumption, it does at price/performance and overall value. It is a $250 card, compared to the $300 of the 4060 at launch. You can still get it at that price, if there's stock, while the 4060 hovers around $400 now. It's also a 12GB card vs the 8GB of the 4060.
So, sure, this is not competitive at the high-end segment, but it's remarkable what they've accomplished in just a few years, compared to the decades that AMD and NVIDIA have on them. It's definitely not far fetched to assume that the gap would only continue to close.
Besides, Intel is not only competing at GPUs, but APUs, and CPUs. Their APU products are more performant and efficient than AMD's (e.g. 140V vs 890M).
Nah, nobody cares about that. Even in their heyday, SLI and CrossFire barely made sense technologically. That market is basically non-existent. There's more people now wanting to run multiple GPUs for inference than there ever were who were interested in SLI, and those people can mix and match GPUs as they like.