This is true if you can scale out (ie you can add resources to your system). But for a robot for example, just adding a GPU can just flop your product completel

This is true if you can scale out (ie you can add resources to your system). But for a robot for example, just adding a GPU can just flop your product completely: you need more battery, more weight, suddenly your unit economics is out of the window... Your next hardware iteration will be very slow to come and very expensive. So here, you better not have a system wasting too much resources pretty early on after the prototype phase.