While I can understand your desire to write better performing code, why C++ over say Go or Rust, both of which offer some modern conventions while being as or better performing with safer code?

In the end, am I better off writing something more efficient that takes 3x as long or get it done and working, and spend my extra time doing things that actually improve things? If I can do 2x as much in the course of a year, would buying a windmill for power generation be a better offset to the “more green” code?