> Bash typically isn't like Python or JavaScript, where certain features are introduced at a particular version and you have to constantly check for them, or not use them outright, or maintain which binary you have installed at all times. One Bash binary typically contains the same feature set as another binary.
While you're right about shell builtins (a lot of which are defined by POSIX anyway), to do anything useful in POSIX shells requires forking out to sed, awk, grep, as well as many other coreutils and CLI tools. Thus you then need to not only confirm whether those tools are also installed but sometimes also which version or even implementation they are (eg GNU extends on POSIX in quite a number of ways from supported features through to how you order and group flags. Sometimes it can be a little jarring jumping from Linux to OSX if you're used to GNU).
That said, I do working in shells. For "getting shit done" very little even comes close to shells in terms of productivity. However shells are generally optimised to the "write many read once" end of development rather than "write once read many".
As an aside, I suspect GP meant to post this comment on https://news.ycombinator.com/item?id=21013150 (Pure Bash Bible - also on the front page) rather than here?