Makes sense. Just like today my phone shows 5G and full bars, but is as slow as dial up.

Yes! Also, early ISPs were often massively over subscribed. They might have fractional T1 line coming into a POP (example: 384Kbit line) with 100 modems off of it. At peak times, you not only got busy signals, but when you did get through, a slow connection because that upstream pipe was full...