There's always at least one of these threads every year, and at some point, it always ends in a bun fight.
I also absolutely detest the class stance, the 'WC parents spoil their children with so much plastic tat, I'm glad I'M not like that. I'm much better and raising non-spoilt children because they only get one gift each'.
No one is a better or worse parent than anyone else, whether they give 1 gift or 20. Fact. End of.
Here's all the reasons that affect how many gifts a child gets:
What they actually want
The budget
How many siblings they have
How many cousins they have, for hand-me-down toys
Other relatives, including GPs
How many toys/treats they get throughout the year
Whether clothes and practical items are considered gifts
Whether stocking presents are included in the total
Whether extras to go with another gift are considered separately
How much someone cares about Christmas
The way in which they celebrate it
For our part, we just have DS. We have no other relatives, no grandparents, no aunts and uncles, except for one lovely great-aunt who gets DS a gift. DS doesn't get treats throughout the year. He is encouraged to save if he gets pocket money, and probably only gets 4 comics a year as a special treat. We also go on holiday, and he has a couple of clubs he goes to. If he needs clothes, I just buy them when he needs them (mostly Vinted or Asda, because he'll cover them in mud and grow out of them, anyway), but no way does he get big toys throughout the year. We save them for Christmas and birthday. When people say they just buy a bike or iPad throughout the year, both I and MC DH are always amazed. To us, unless it was completely broken (then fair enough), it would be a big present you would have to wait for.
I come from a WC background, and DH from a MC background that was well-off enough for him to go to private school. We are an above-average earning family, but not wealthy, living in North Yorkshire. We buy DS around 10-15 gifts, not including stocking fillers, which are things like playmobil figures and choc santa. He loves everything, plays with everything, and at least 3-4 of those gifts are books.
I think if you feel snobby about those who buy more than you, or have a chip on the shoulder about those who buy less, you might want to remember the gifts are being bought for the season of goodwill...