> We spent a lot of time these last 40–50 years chasing performance above all else, prioritising it before safety, expressiveness & development time.

I'm not sure I agree with this assessment. Certainly some developers have been targeting performance (particularly compiler devs. Arguably UI devs). However, in corporate development, performance has ALWAYS come second to development time. The only time performance matters is.. well, when it does :). That is to say, it only matters when slow things are causing unhappy clients or missed deadlines.