Indeed DD. I think the first big change was the Hub and Spoke era where pax found that their bags did not make the intersection, so started carrying more in the cabin. This was the era of the enormous shoulder carried 'suit bags'. Then came the era of LCC and the desire to turn the aircraft faster than ever and made the cargo hold a no-go zone. Money is always the driver and pax found the lower fares what they wanted.
I have long thought the standard evac tests are pointless box-ticking. I am fortunate that in 54 years of paxing, I have never had an emergency evac but I try and book seats closest to a door.