I guess, technically, if I had had a kid at 18-20 and my kid had done the same, maybe it would be possible. Then again, a younger step-sibling is already a grandmother.
We were still supporting navigator and/or communicator when I was working in my first IT job doing tech support for a dial-up provider.
To be fair, if you worked in the government (including the military), old apps and programs could last a long time. I wasn't THAT old when I used Netscape in the Army. Plus, there's precocious kids who do stuff like use browser and command line stuff (and even code) before their age is in the double digits.