> Sure, maybe for some esoteric edge cases, but 5 mins on https://learnxinyminutes.com/ should get you 80% of the way there, and an afternoon looking at big projects or guidelines/examples should you another 18% of the way.

Not for C++, and even for other languages, it's not the language that's hard, it's the idioms.

Python written by experts can be well-nigh incomprehensible (you can save typing out exactly one line if you use list-comprehensions everywhere!).

Someone who knows Javascript well still needs to know all the nooks and crannies of the popular frameworks.

Java with the most popular frameworks (Spring/Boot/etc) can be impossible for a non-Java programmer to reason about (where's all this fucking magic coming from? Where is it documented? What are the other magic words I can put into comments?)

C# is turning into a C++ wannabe as far as comprehension complexity goes.

Right now, the quickest onboarding I've seen by far are Go codebases.

The knowledge tree required to contribute to a codebase can exists on a Deep axis and a Wide axis. C++ goes Deep and Wide. Go and C are the only projects I've seen that goes neither deep nor wide.