> If you look at your typical phone or laptop SoC, the CPU is only a small part

In mobile SoCs a good chunk of this is power efficiency. On a battery-powered device, there's always going to be a tradeoff to spend die area making something like 4K video playback more power efficient, versus general purpose compute

Desktop-focussed SKUs are more liable to spend a metric ton of die area on bigger caches close to your compute.