Well, I guess I was coming from a position that hobbies can be as irrelevant as you want and use whatever age of tech you want, whereas if you're doing this for a living you generally want to use the tech of the day. Sometimes this tech is old stuff that survives and thrives to this day, especially with CS concepts that won't really age (like data structures for the most part), however there is some stuff that just is not efficient enough to use for making money, sadly, since that's mostly about efficiency these days and not usually about doing things perfectly right, or even to any decent quality standard, sadly.
I, personally, use old and/or shitty equipment and techniques when I do woodworking, for example, like using chisels to make mortise and tenons rather than a fancy plunge router, or just skipping those and using one of those fancy Festool machines that do the "fancy biscuits".
When I program, I mostly use Python these days (don't judge me!) and I tend not to use third party extensions or libraries, so I guess you could say I use the "old school" technique of using the standard library for Python for everything, where if I were trying to make money I would be using `poetry add` for things like requests, flask, etc.
I think irrelevant and out of date tech can be used for making money, but it's a bit harder that way. I personally like using the "old ways" quite often in my personal and professional lives, and not trying to optimize my personal or professional life as much as most do, but I can see that I'm not the norm there, and most people just memory-hole old tech and move on to the next house of cards.