Bash just sort happened to be the lowest common denominator in most unix style environments. Because it just sorta ended up being the default. Unix ended up being this different thing where each distro seems to be kind of unique. Then on top of that they are very easy to customize. So while one distro you can assume a particular python level the next disto python is totally optional. Mix in containers and docker images and you have a new level of 'what may or may not be there'. Ah but you may say 'oh just use tech XYZ' that may or may not have the exact same issue as using python in its place. So either 'deal with it' and install what is needed and keep it up to date. Or 'play the LCD game' you use only the bare min and hope you can build something useful enough in bash when another lang may be more appropriate.