Yes, there's a good deal of Bah Humbug going on here.
You can opt out of the elements you don't like. Even with extended family pressure, you can draw a line and let the chips fall where they may. If family members are so put out that you'd be punished for doing things your way, maybe they're not people you want in your lives anyway - it's doubtful Christmas is the only occasion they exercise their narcissism.
I'm in the US where we have the full turkey dinner with all the trimmings (but none of the gift giving) at Thanksgiving, about four weeks before Christmas. We then do it all again at Christmas - usually minus the turkey; I normally do a rump roast.
I do the roast spuds, Brussels sprouts, etc, because that's what I associate with Christmas, but I have friends who do all sorts of different meals, or head to a hotel or restaurant, or leave for a holiday somewhere warm.
Traditional American Thanksgiving dinner and desserts are far more universal than American Christmas fare.
My family also has a festive Christmas Eve dinner, and open presents from each other and far flung family that evening. Boxing Day isn't a thing here. I serve heated up leftovers, and then leftovers gussied up with salad or fresh bread until at least five days after Christmas.