It's not just a syntactic difference. It's a huge UX difference that one operator always does an addition on both numbers and numeric strings, and another operator always concatenates both numbers and numeric strings.

The looser your typings the more it matters, and spreadsheets barely even have types.

Yeah, I spend more time doing data manipulation in python than in excel, so I thought that excel would do that as well.

In C? How?

sorry, meant cpp! C (apparently) uses a function that more closely resembles Excel

C has strcat but that only does the easy part - allocating and freeing the memory is still the caller's b job.