Another thing to remember about the 'old days' (80's and earlier) is that in addition to there being no public Internet for (most) people to hook into[1], was the expense of actually using the phone. Except for local calls (pretty much people in/near your city), everything was metered: we had zone calls where calling someone more than ~5-10 miles away incurred per-minute costs (iirc, $0.10-0.20/min), long distance calls (>30-50 miles) were more expensive (iirc, $0.30-0.50/min), and international (esp. overseas) calls were insane (you would typically try to keep conversations very short as the costs would start at $1-2/minute.)

So amateur radio was a very cost effective way to communicate with like-minded people with very rapid payback. That said, a lot of people just liked chatting with strangers from far away places.

[1] There were commercial services and BBS's but they were also relatively niche until the late 80's largely due to the actual cost of the phone call as described above.