But you didn’t access a BBS via an ISP, that’s one of the key differences. You dialled your modem directly into the BBS

BBS’s pre-date what we know as the internet - that is, commercially available interconnections via an ISP to a “wider web” of servers. Pedantically you can argue there is overlap with the period when only universities and a couple of tech companies were interconnected but calling that the internet is like calling a horse and buggy a car because it has wheels and carries passengers

Re-read what they said. They’re talking about modem dialup to a long distance number, so the phone call the modem made was long distance and hence charged at the higher rate.

It’s ok to not get it, this is pre internet and a very long time ago