For whatever reason, RPN didn’t really succeed in the general marketplace, and you might wonder why it was ever a thing. The biggest reason is that RPN is very easy to implement compared to working through proper algebraic, or infix, notation. In addition, in the early years of computers and calculators, you didn’t have much to work with, and people were used to using slide rules, so having something that didn’t take a lot of code that matched how users worked anyway was a win-win.
With RPN, there is no ambiguity depending on secret rules or parentheses, nor is there any reason to remember things unnecessarily. Processing RPN, on the other hand, is easy. If you see a number, push it on the value stack. If you see an operator, pop off enough stuff from the stack, do the operation, and put the result back on the stack.
See https://hackaday.com/2023/06/21/in-praise-of-rpn-with-python-or-c/