That makes no sense. Just because I do not know X, it does not necessarily follow that I am not required to know it, not at all. I might need it for my job, or my future job. I might need it for a Linux distribution I just installed, and so forth. Or perhaps I am already using iptables, but I do not know it.
To your C++03 analogy, I wouldn’t recommend learning C++03, but I also wouldn’t recommend solely learning C++23 either. C++20 and 23 have some really cool stuff in them that can definitely make your code cleaner, but there’s a lot of codebases that are stuck on older versions (at $JOB one of our target platforms is stuck on C++17 and will never get an upgrade so we can’t move the codebase forward until we abandon that kit).
I for instance have never really used iptables in anger, but have lots of experience with nftables and pf. I’ve used both in a professional setting. People can be made aware of iptables, but unless there’s a need to know it, I wouldn’t recommend picking it up now. And you’ll know if you need to learn c++17 or iptables, or python 2.7.
