Of course it does, seccomp, developed way before pledge :))
edit: and this number does not even include the ports available with pledge support, among others chromium.. and the fact that they were capable of adding pledge support this quickly says a lot, imho, about the implementation differences between libseccomp and pledge.
Pledge is instrinsic. You have it right from the beggining with C and Perl. And it's straightforward to use.