You’re not imagining it—shingle weight has definitely dropped over the years. Manufacturers have trimmed material to cut costs, and you can feel it in the bundles. I’ve noticed the granule loss too, especially after a tough winter. Up here, the freeze/thaw cycles really chew up the lighter stuff. Architectural shingles hold up better, but yeah, they’re pricier and heavier to haul up a ladder.
I get where you're coming from, but I’m not convinced the lighter shingles are always a downgrade. I’ve used some of the newer brands on a low-slope garage, and they handled two winters just fine—no more granule loss than the old stuff. Maybe it’s more about the install or attic ventilation? Some of my neighbors with heavy architectural shingles have had curling issues too, so weight isn’t the only factor.