I missed almost 10 years of cruising, coming back to the fold in 2007.
Biggest change? $$$ wise ...
The hysteria about the "upsell fairy".
Upgrades used to be free on cruise lines and almost automatic if you had status.
I speak as a past frequent cruiser and as a working travel agent until the early 90's.
Now it is quite clear that a key part of the ship dispatcher's job is to monetize every operational upgrade.
Passengers would now outbid each other to receive what used to be given out FOC.