Similarly I'm not sure Octave ever really got that polish to compete with MATLAB.

SPSS is hilariously painful to use. Still it's only losing ground ever so slowly. PSPP remains almost unheard of among SPSS core users.

I am not sure Octave ever had to put on that much polish. It just had to be decent enough to save $$$$ vs a Matlab license. If it can drop-in run the code that has been keeping the lab going for decades, good enough.

MathWorks offers a huge list of "toolboxes", domain specific extensions that cover a lot of features in each domain. Replacing Matlab isn't about the core language alone.

Which often means that e.g. loading an image for displaying it increases cost by a few thousands

The price tags are wild for sure. But the sheer number of supported features is what makes them attractive. Cloning that completely is practically infeasable.

> It just had to be decent enough to save $$$$ vs a Matlab license

And it failed at this.

I did my PhD with Octave. Sure, I did not have this nice convex optimization toolbox. But I had everything else I needed and did not need to wait because people arrived earlier in the lab and grabbed all floating licenses of, for instance, the communications toolbox.

However, I switched to Python during the last years.