Nowadays I'd probably just ask Claude to figure it out for me, but pre LLMs, WL was the highest value tool for thought in my toolbox.
(Edit: and they actually offer perpetual licenses!)
If this was open sourced, it had the potential to severely change the software/IT industry. As an expensive proprietary software however, it is deemed to stay a niche product mainly for academia.
It's $195/year for a personal license. And only $75/year for students. Their licensing model is pretty broad.
I don't remember what the pricing has been throughout the years. But I do remember that for some of the time I couldn't really afford Mathematica. And the license I wanted was also a bit too expensive to justify for a piece of software that only I would be using within an organization.
Because it is also about enough other people around you not being able to justify the expense. And about companies not wanting to pay a lot of money for licenses so they can lock their computations into an ecosystem that is very small.
Mathematica is, in the computing world, pretty irrelevant. And I'm being generous when I say "pretty": I have never encountered it in any job or even in academia. People know of it. They just don't use it for work.
It would have been nice if the language and the runtime had been open source. But Wolfram didn't want to go in that direction. That's a perfectly fine choice to make. But it does mean that as a language, Mathematica will never be important. Nor will knowing how to program in it be a marketable skill.
(To Stephen Wolfram it really doesn't matter. He obviously makes a good living. I'm not sure I'd bother with the noise and stress coming from open sourcing something)