I'd imagine it always varied by individual, then as now. Now that you point it out, the ultra light crowd seems to have had a lot of influence in bike camping as well as backpacking. Still, there are those that pack everything: a laptop, a phone, a GPS, a camp seat, etc.
I definitely rode a lot from junior high through high school, but didn't try bike touring until summers while in college. I never broke anything, but I didn't do *that* much of it. The most epic one for me was about 24 days, IIRC.
For sure much of my own camping gear is lighter than the vintage stuff, but even BITD you
could find light gear, if sufficiently motivated. Down bags were always light. Hoop tents were light, if you even bothered with a tent. Water purifier? What's that?

Actually I think tents have been going backwards the last couple decades, but that's pretty OT. In general though, yeah, gear was heavier. I did have one buddy who rode across the country on his Trek 720, and he had and used one of those Optimus suitcase stoves. It was hilarious. Must have weighed like 8 lbs.*
EDIT * Ha, I looked it up and they only weighed 28oz full. They
looked like they weighed 8 lbs.
