Where this happy infix world goes wrong is precedence rules, especially where they're different between different languages.
The numerical operators, with the Boolean operators, negation, comparisons, maybe implicit type conversions as well. Maybe && as separate from &. Maybe user defined operators with different precedence to the builtin ones.
Maybe the large precedence table you have to keep in working memory to use the infix conventions is still simpler. Maybe even when there's a style guide saying to put lots of parentheses in as well. It starts to be difficult to fit a definition of simple to the observations though.
The numerical operators, with the Boolean operators, negation, comparisons, maybe implicit type conversions as well. Maybe && as separate from &. Maybe user defined operators with different precedence to the builtin ones.
Maybe the large precedence table you have to keep in working memory to use the infix conventions is still simpler. Maybe even when there's a style guide saying to put lots of parentheses in as well. It starts to be difficult to fit a definition of simple to the observations though.