While it is an important holiday for Christians, it’s widely celebrated by non Christians and most of the traditions predate Christianity as European winter celebrations. It includes bits of Germanic Yule and Roman Saturnalia celebrations, both which predate Christianity.
This is mostly pop history, dating back to anti-Catholic propaganda from zealous Puritan reformers who wanted to excise any trace of what they saw as pagan contamination. The bulk of Christmas traditions are distinctly Christian, and very little of Saturnalia in particular was carried over into the new holiday. Perhaps the biggest influence it had was the tradition of communities electing a 'King of Mischief' to preside over festivities -- a practice that hasn't even survived into the modern day!
Of particular note is the Christmas tree, which as far as we can tell originated in the (decidedly non-pagan) 16th century:
"The earliest mention of customs like Christmas trees are actually ascribed to Martin Luther. The story goes that during a winter evening stroll Luther was overcome by the brilliance of the stars in the night sky, painting the background over the evergreen forests. In order to capture that moment Luther cut down and erected a tree in the main hall of their house, covering its branches with lighted candles" (Bruce David Forbes, Christmas, a Candid History, 50).
I don’t think what you are saying is accurate- I was looking up the history of most of the regular things people do as American families, and almost everything I could think to look up had pretty clear non Christian origins. It sounds like the Romans even cut evergreen trees and set them up indoors for Saturnalia. By all accounts the Catholics only changed it even to be in the winter to try to co-opt existing winter Solstice celebrations. It is hard to figure out the real history of things with so many motivated accounts…
Overall, specific rituals aside, having a big family celebration around the winter solstice really seems to do wonders for the mental health of people at high latitudes- and has been done consistently since long before Christianity. As a parent in a non Christian family, I find it to be incredibly valuable and important and I take it pretty seriously, but without any sense of it being religious.
Every year, some people need to marginalize Christianity's contribution to Christmas despite ample evidence to the contrary. I attribute it to an ignorance of how religion digests culture and evolves, plus the usual resentment towards that religion in particular.
There's actually a neighborhood, where everyone who lives there is Jewish, and they go all out on lights. Even get the houses networked together so they can do effects across the whole street. They also post a lot of how to videos regarding xlights and stuff
