The interface could be better, but depending on what you're doing, you likely want a protocol ack, not a network ack anyway. Ex: If you send a file, you probably want to know that the file write succeeded, not just that the program that's supposed to write the file received it.

In today's world of janky TCP optimizing middleboxes, an ack just means you don't need to resend it, not that it arrived at the kernel of your peer; and it never meant the program at your peer read it.