Five years ago, paying a fee for unlimited texting sounds about right. Perhaps 10 years ago, it was more common that you'd be charged a fee (perhaps $0.10 or $0.20) for every text sent or received. For this reason, texting took quite a while to catch on in the US.
As for minutes, most companies no longer have a concept of "long distance" (international is still a thing). So for calls within the country, there is no distinction between "incoming minutes" and "outgoing minutes" -- they're just "minutes". If you're making an international call, I believe you're changed a per-minute surcharge. If you're receiving an international call, you are billed just for the "minutes" used, with no international surcharge.
Simple, right? Of course, none of this is law or anything, so it's really up to the individual companies to decide how to do things.