If inference cost is so cheap and negligible, then we'll be able to run the models on an average computer. Which means they have no business model (assuming generosity from Meta to keep publishing llma for free).
I think they mean running inference. Either more efficient/powerful hardware, or more efficient software.
No one thinks about the cost of a db query any more, but I'm sure people did back in the day (well, I suppose with cloud stuff, now people do need to think about it again haha)