That's probably because the 3 paths are orthogonal: becoming a better IC would make one a worse manager; and becoming a better manager wouldn't make one a bette

That's probably because the 3 paths are orthogonal: becoming a better IC would make one a worse manager; and becoming a better manager wouldn't make one a better exec. Just like an exec wouldn't turn into the business owner no matter how hard one tries. The ladders that connect ICs with execs exist, but they are outside of the building.