Yes there was a reason as Perl took inspiration from Lisp - everything is a list- and everyone knows how quick C's variadic arguments get nasty.
So @_ was a response to that issue, given Perl was about being dynamic and not typed and there were no IDEs or linters that would type-check and refactor code based on function signatures.
JS had the same issue forever and finally implemented a rest/spread operator in ES6. Python had variadic from the start but no rest operator until Python3. Perl had spread/rest for vargs in the late 80s already. For familiarity, Perl chose the @ operator that meant vargs in bourne shell in the 70s.
Not only normal arguments like we get in C or Pascal, but there's keyword arguments, you can have optional arguments, and a rest argument, which is most like Perl's @_. And that's not even getting into destructuring lambda lists which are available for macros or typed lambda lists for methods.
So @_ was a response to that issue, given Perl was about being dynamic and not typed and there were no IDEs or linters that would type-check and refactor code based on function signatures.
JS had the same issue forever and finally implemented a rest/spread operator in ES6. Python had variadic from the start but no rest operator until Python3. Perl had spread/rest for vargs in the late 80s already. For familiarity, Perl chose the @ operator that meant vargs in bourne shell in the 70s.