on the RPN mentioning sharp pc-1211, v.albillo, el-506w and recurring topics

[franz.b]

you made me think of an important detail: seeing partial results helps a lot in understanding what you are doing and prevents gross errors, as has already been said.

It is true that most calculators are algebraic, but most people look for a family environment and do not try the pros and cons of the alternatives, so the builders are not interested in proposing something different without courage. Android vs. WindowsPhone vs iOS teach: those who have a system hardly leave it, whatever the advantages or disadvantages.