Crossfire/SLI is not a viable scaling solution when it doesn't improve latency and developers have to support it. I'm not surprised it's been phased out.

The next step in scaling performance is chiplet based packages like Zen. Since wafers are getting more and more expensive the chiplet approach seems like the only way to keep solve for costs, yields, heat density, etc. RDNA3 is supposed to be the first chiplet-based arch. I'm really excited for that. Imagine 4x40CU chiplets with an IHS the size of a threadripper, boom.