One major problem is that some version of Python was supplied with most Linux/Unix distributions - this allowed people to get started without thinking about thi

One major problem is that some version of Python was supplied with most Linux/Unix distributions - this allowed people to get started without thinking about this problem and then end up too deep in the hole by the time they realise. Other languages or OSes that don't have their interpreter bundled forced you to think about the problem from the start and build a way to ship a stable version of the runtime with your application. Python, as a server-side programming language is not too bad. You can standardise on a version and bundle that interpreter version with your application itself in whatever artefact you produce (whether a Docker container, tarball with Python binaries + source or entire VM image with the right Python version installed). Desktop distribution is a pain, but that's not limited to Python; any language that can't compile to a native binary will have this problem - even Java, despite having much better backwards compatibility, still isn't prefect and sometimes requires an older JRE to be installed on your target machine.