I have followed a few threads on MN on this subject, many of the invitees not wanting to go for one of the following, financial constraints, work commitments, juggling childcare., not enough annual leave to cover that outing and a family holiday. All valid reasons imo. for turning the invitation down, furthermore that should be accepted with grace by the person who has issued the invite. Sadly that is often not the case. On one thread, the imperious invitation issued by the bride's mother said something along the lines, bearing in mind I think the cost of a trip abroad for the hen do was going to cost something in the order of £1,000 "you all have a year to save up, no ifs no buts about the cost" Absolutely staggered at the expectations and front of some people none of their business as to what people can or cannot afford. The woman who started the thread and had the invite didn't really want to go due to the cost and having to take time off work, childminding etc. Then at some stage down the line, she had to do an extra shift, hospital worker I believe and missed some Zoom meeting to discuss all the prospective dross they were having to stump up for. Upshot, she was severely admonished for missing the meeting, ostracised by some which happily gave her the impetus to drop out. Unanimously the other posters spurred her on giving her the courage to stick with that decision. Then both she and her husband were ceremoniously dropped by both bride and groom and I think they had their wedding invitation withdrawn too.
Honestly, I feel sorry for many of these young women these days, it honestly wasn't a thing when I was young, maybe a meal out with some close friends but not these expensive week ends, a full week even. often abroad, for something, it seems many feel under immense pressure to go along with. The other thing many state, that they only often know the person getting married and are forced to be closeted with others who they later find the don't like.
All in all it's got sod all to do with marriage and a couple's life ahead. It's such a load of unnecessary bollocks extravagances.