Growing up in the 60s and 70s... I had my senior year (age 18) prom, not anything as extravagant as they are today... yikes, things have gotten out of control! My boyfriend and I went out to dinner (you get a lot of grown up attention if you are in formal wear) as you do, then to the prom for dancing. After that we changed to shorts and tee shirts and drove to the beach to crash out in sleeping bags with about twenty other couples after a beach bonfire, roasting hot-dogs and marshmallows. Those were the days! 
As people did not live together before marriage, we had bridal showers to help the new bride set up home. Anyways, now people don't usually need home essentials as they probably already have their own homes or are living together.
I much prefer a bridal shower to a 'hen night' or bachelorette party as they do there. Hen do's here make me cringe. And to expect someone to fly to Ibiza or Vegas for it is very cheeky. My niece had three in one year and it drove her broke. My soon to be official DIL is having a local spa day, then dinner out. No drunken revelry on the cards.
Baby showers are useful... usually given in the 8th month when we know all would be OK. Nappies and other baby consumables that get expensive as time goes on were the usual gifts, not posh baby outfits. Women who knitted would make layettes or receiving blankets, etc.