Re: C
for the most part, performance comes from good algorthims
Complete rot. The vast majority of embedded, business, and personal1 software is not CPU-bound, so "good [algorithms]" have relatively little effect on performance.
good algorithms come from developer productivity
What a bizarre fantasy.
"Good" (by some metric) algorithms either already exist and are only waiting to be discovered, if you're a Platonist, or come from computer scientists - that is, people who do research into algorithms. The use of "good" algorithms in software is overwhelmingly determined by the use of libraries and frameworks supplied by a relatively small cadre of developers and used by a much, much larger group of application developers; since the latter group tend to lag the former by years, if not decades, the productivity of the former is not a constraint.
1Except for graphically-intensive games, which these days do most of their computing on GPUs and not general-purpose CPUs anyway.