It’s an interesting one - I’ve seen it from both sides. I grew up in a very large Irish American family with loads of cousins. Christmas was easily 50 people, I’m not kidding! Whenever we all got together there was no way one person could be expected to cater everything, so the “host” usually provided the venue and the main course, as well as a decent selection of wine, beer and soft drinks. Starters, sides and desserts were always parcelled out among the aunts and female cousins (and yes, it was always the women!) without the slightest complaint. It was also expected that you would bring along some alcohol too.
Weddings, however, are a completely different matter. They are always, always with a full dinner and open bar. They cost thousands but there is no getting round it. Guests do not pay a penny towards their consumption BUT they are expected to “cover their plate” (i.e., pay their “per head” cost) with their wedding gift. It’s nuts, I agree, but no one would dare break the custom.
When I moved to the U.K. I married into a wealthier but much smaller family. It is seen as almost an insult to the host to ask what you can bring to a gathering - it implies they couldn’t handle it themselves. I remember my DH being embarrassed when we were invited to a party by our NDNs and I asked what I could bring. So I am now well used to catering for up to 12-14 for Christmas without batting an eyelid. That said, no one would dream of turning up at an invitation for a meal without bringing something, like a bottle of wine, but it is usually something that the host can enjoy later and is not expected to be opened or shared by the company.
Our wedding was a bit of a culture shock on both sides as we had it here but I insisted we have an open bar. There was no way in hell I was having relatives fly all the way over to the U.K. and make them pay for their own drinks. MIL was scandalised at the thought and convinced it would be abused but she wasn’t funding it so I got my way.
We do sometimes go to gatherings like bbqs of DH’s school friends and, as used as I am to bringing something, I do have to say I find the concept of bringing my own meat a bit
.