If you look at the internal state of the typical physical calculate it's a beautifully simple machine that tries to catch the balance between RPN and logic... except it has stupid nonsensical human rules interjected.
So, every time this article where points out "actually it's more complicated than it seems" is where historically somebody has made deliberate design decisions to do it 'the dumb way' even though it adds complexity, to force something unnaturally.
And what you end up with is something that's half intuitive, it's in between the two systems, but it's more complicated than it needs to be.
Please, I would much prefer device for RPN calculation, that follows consistent logic, rather than silly imposed rules.
4+7*3 etc.
or 4 7 + 3 * =
Where the latter is much closer to what we do in our heads and conceptually think about it.