They said they would wait until there was a meaningful increase in the power or efficiency they could get out of the form-factor.

The OG deck launched 3.5 years ago, and since then not much has changed. The steam deck GPU has 1.6 TFlop of FP32 compute at 15W. AMD’s newest low-power APUs have 2.3 TFlop of FP32 at 28W - nearly double the power for a <50% theoretical performance gain.

A semi-custom APU (that removes the useless AI engine) would compare more favorably, but we are still talking about maybe 20% more performance, not exactly game changing for the cost.