Again I totally agree, but a lot of the conventions also started when as the gift-giver the most you had to do is tag your other friends and say "are you buying them $Thing That Every Single NewlyWeds/NewParents Ever Will Need", because you could reasonably assume that they had absolutely nothing except handmedowns to start a new house or care for a new baby with.

It falls apart in modern Western culture because we tend to have already established independent households, stuff is way more disposable and at the same time often less expensive, etc. So then you have to run around trying to figure out wtf someone wants and doesn't have and won't buy for THEMSELVES between now and the event and AUGH.