[fddr]

I am genuinely surprise at how confidently you (quite wrongly) diagnosed my problem.

What I did mean, was that for my use cases, I found Mathematica was superior to the alternatives. You are welcome to think this was because I was lazy or misguided, but it was definitely not because I liked not having to specify domains for my variables (and I do remember having to write Assuming[p>0 && x \in Reals, ...] and the like often, it definitely does not assume everything is a positive real).

One thing I used Mathematica a lot for was numerical integration of ODEs (that had been derived using the CAS part of Mathematica and had some pretty nasty coefficients). NDSolve in my experience was just better than competition. You can definitely get nonsense out of it, but with a modicum of care it works incredibly well.