Secondly the presence of all these utilities on a machine is far from guaranteed - expecting Python to be present is no more or less likely.
Why do you get to declare what is acceptable (using UNIX tools) or what's now obsolete (SSHing into a host)? It's rather presumptuous to believe you can speak for everyone. Perhaps you only ever deploy code using k8s and never need to use a command line but that doesn't mean we all do. There are many reasons one would use these tools and approaches (fun, small scale, investigating problems, anything).
For what it's worth, my bosses all the way up to CEO of a 50k person company were all pretty pleased with the working practices I used (medieval things like strace(1), perf(1) and sort(1)) to save thousands of servers' worth of CPU. I'm not advocating for editing code live over SSH but there are still plenty of legitimate reasons to SSH into a server and use UNIX tools.
Since you're clearly trolling I'll leave it here.
Of course lots of people do it because they enjoy it or are used to it, and for them cost and related considerations don't matter. The same way that lots of people ride horses.
So you don't need to SSH to debug, you'd just re-deploy another container or something.
However, there's an <<extremely>> long tail of places, equivalent to mom and pop stores, where SSH will still be in use for a long, long time. I include antiquated banks or government in "mom and pop stores" for the purposes of this discussion :-p
I've still never seen a place where this was true.
At some point you always run into a situation where you need to see what's happening inside the container in production at a level of detail that isn't available except by directly connecting. So you attach a sidecar with SSH, or you deploy a debug version of your container that runs SSH, and then you SSH into your container and see what's happening.
(Again – an honest question! I was never formally instructed in these matters.)
On macOS, there's still only Python 2.7 pre-installed (Xcode then goes ahead and also installs an equally outdated Python 3 version). On Windows the Python executable is an empty stub which opens the app store.
I wish the situation would be better.
1. The version of bash is even more out of date (Dating back to 2007 on current macOS releases).
2. #!/bin/sh Could give you any one of a number of slightly different shell implementations.
3. The differences between Python versions are clearly documented, and, while painful, possible to work around. The differences between shell versions can be far more subtle and more difficult to discover.
4. You not only need to deal with the shell version, but the version of every tool you use as well.
Shell is portable in a way nothing else is, same reason people use Excel instead of code or PHP instead of literally anything.