Most software engineers have the wrong focus.
They focus on efficiency rather than effectiveness.
What's more important? Solving a $ problem with 99.999% efficiency or solving a $$$ problem with 90% efficiency?
My question likely made someone recoil. Big O-notation is taught in college. You hear the horror stories about systems crashing due to 10x nested loops.
So yes. Efficiency does matter. It just matters less since there are infinite wants and scarce people+time to solve all them.