Not entirely sure what you're responding to, my Infinity Cache comment or the statement about the "Raster advantage"
Raster Advantage is just benchmarking by TFLOPS, it seems pretty consistent across lots of cards and tests. It's possible that there are arrangements of the CUs/SMs that tilt one way or the other, but I don't have the data to test those. Perhaps those do, in fact, lean against the Steam Deck in this case.
Infinity Cache - yeah, absolutely, the architecture is screaming out for it. But we can't test with IC on and off. In the case of the Steam Deck specifically, we can test what happens when we throw significantly more bandwidth at it. It doesn't make the Deck seem bandwidth starved.
It's highly possible that IC would offer performance benefits that are more about cache friendly workloads, than bandwidth usage per se. On balance, the benchmarks seem to suggest that the lack of the IC isn't dragging the Steam Deck by 30%. But there might be better benchmarks that tease it out. I'm not 100% confident on this at all. Not even 70%.