For me, the main appeal to MATLAB was the REPL experience, allowing me to experiment with ideas and inspect results in the UI. Python notebook have bridged the gap a bit, but always require a combination of libraries (with different docs & design choices) to write a single script.

Yup, for both Matlab and Maple the big feature was the Jupyter notebook experience right out the box. On top of that, at the time it had a pretty high number of math functions implemented.