ThreeMyselfAndI (good name btw), I think what you are doing is merely not being able to understand something which is so far outside your experience that it has no personal register. Of course the emotive language you use about failure and being sad is borne of conjecture. You're wrapping up the suggestion of a £10 gift inside a massive wad of fear of bullying, disappointment, rejection, a break with tradition and so on. I can probably understand why you'd do that, parenthood is riddled with guilt and fear but it's also important for you to understand that your sweeping generalisations are unfounded.
My DC is in Y2. I fully expect, in fact I know that her friends will receive some very expensive presents. The sorts of gadgets I don't understand as an adult. Will dd feel inferior? No. Not a jot. She has the self awareness and confidence to feel happy with who she is and what she has. She knows and appreciates value not just of gifts but of the time and love bestowed upon her.
I truly don't judge families who provide hundreds of pounds worth of gifts. I could couch their decisions in hyperbolic terms. I could wax lyrical about the reduction of a season of family, goodwill and togetherness down to a pile of bought things and mass consumerism. I could hint at the sadness of a child who expects, a child who equates presents with affection. But I would be doing myself a disservice. It's an ignorant and ridiculous way to cast yourself as right and other people as wrong. The decision of how much to spend is just that. One decision. It is not a reflection of how much a child is loved, how much that child will appreciate its Christmas and it's not anything I'm qualified to judge in isolation.
I know a few children whose parents will spend nothing on them, financial or emotional and I do feel very sad about that. I know as many children who will have ££ spent on them and I feel quite sad about them. The sadness is nothing to do with the money. Money is just a tool. Thankfully, I know hundreds more children who will have bright, shining and beautiful Christmases irrespective of what's under the tree on the 25th.
I will go on believing that the gifts are a bonus. An extra, brilliant thing on one of the days of Christmas. I do secretly believe, however, that it's nice that it's a tiny part of everything else.
Now you must excuse me, I have a Boxing Day treasure hunt to plan for and mincemeat to stir.