NVLink matters if you want to combine a whole bunch of GPUs, e.g. you need more VRAM than any individual GPU is available with. Many workloads exist that don't care about that or don't have working sets that large, particularly if the individual GPU actually has a lot of VRAM. If you need 128GB and you have GPUs with 40GB of VRAM then you need a fast interconnect. If you can get an individual GPU with 128GB, you don't.

There is also work being done to make this even less relevant because people are already interested in e.g. using four 16GB cards without a fast interconnect when you have a 64GB model. The simpler implementation of this is to put a quarter of the model on each card split in the order it's used and then have the performance equivalent of one card with 64GB of VRAM by only doing work on the card with that section of the data in its VRAM and then moving the (much smaller) output to the next card. A more sophisticated implementation does something similar but exploits parallelism by e.g. running four batches at once, each offset by a quarter, so that all the cards stay busy. Not all workloads can be split like this but for some of the important ones it works.