But in your example, your only describing one specific task (n=1). The issue is that time accumulates non linearly as the number of tasks increase. i.e the petrol stations must be able to supply enough petrol to all customers that drive the most inefficient car.

The culture of "developer time is most important", makes overall system performance someone else's problem, because "my program is fast enough when I measure it off the wall clock". But who's responsible to fix overall system performance, and how can they fix it? I think a lot of people would just upgrade their RAM, CPU or IO to solve the issue (create more petrol stations), rather than asking vendors to change the programming language, or to be more conservative on RAM.

And because there's costs to switching language stacks, people will stick to writing in the language they are comfortable in, so critical business systems get written in slow languages.