Justine, my ex and her wife, being in their 60s, did not see the need for a traditional wedding. So they just had a party:

https://medium.com/the-junction/conversation-with-my-wife-154-573ffa4def31

They almost didn't see the need for a traditional marriage, until Linda needed to be driven onto a military base (she's a Naval reservist) and Carol couldn't take her, since she wasn't eligible for a dependent's ID; and then Carol was hospitalized, and Linda couldn't see her because she wasn't "immediate family." Still waaaaay too many legal benefits that add up for married couples. (As I try to explain to some of my millenial couple friends, all genders and preferences. They don't say "Okay, boomer!" out loud, but I can hear it.)

As to why the youngr crowd still likes to have "traditional" weddings that don't make much sense? I was hoping you'd have an answer. <sigh> Maybe still too many little girls growing up wanting That Big Wedding?