I didn't have broadband at home in 1995 though probably had 28k bps or something like that over a phone line--which still charged per minute outside of you immediate set of exchanges. Not sure I had a cell phone. If I did it was for occasional use for specific purposes. And you didn't really have video on demand for another decade, at least. Very little ecommerce.
Certainly 1985 was even more all this; a lot of people didn't even have VCRs for time-shifting at that point or home PCs. Prior to joining a company that had an internal email system in 1986, I didn't even have email except in a very fragmentary way through organizations like CIS.
1200 would have been unbelievably fast in 85. Try 300 acoustic couplers. I was a student lab tech in my high school in 83 or 4. Being the ahole I was, I’d walk into the lab and whistle loudly fully knowing that everyone’s terminal would freak out with line noise. BofH indeed.
I have to disagree with your timeframes a bit at least for home PCs. I never had an acoustic coupler but I had a 1200 and subsequently faster modems starting in about 1983. I did use acoustic couplers on teletypes in the mid 1970s.
I'm not surprised that a high school computer lab would have been lagging by a few years. I'm guessing I was at a 1200 direct phone jack modem connection in 1985 (which would have been my first modem).
Now drop them in 1985 instead. No video on demand or highspeed connections or cell phones. CONNECT 1200.