Exactly this. I think people are doing more Christmassy things because there are way more Christmassy things to do, and since they often cost money, people with more money can do more of these things.
Of course there have always been and still are plenty of free or low-cost events (our local community centre had a brass band out playing carols yesterday, my 3yo loved it and we donated £1 to the bucket). But given the cost of living crisis, most people are just not spending as freely as they used to, so every business is using Christmas as a way to drum up sales. This is not a new tactic, of course, but it's definitely gone into overdrive as the Christmas season has grown to be two months long, and social media enables people to broadcast and amplify their activities. Everywhere has a Christmas "experience" you're invited to pay for, photograph and share.
I feel like the Christmas feeling, for me, tends to come from lovely walks in cold weather, cozy pubs, brass bands playing carols (love me a brass band!) and time with family. Of course, aside from the pub, those things don't cost very much so capitalism demands the creation of paid-for experiences to drive spending. Every park and outdoor space has a light trail now, for example - but why do this when we can walk around our neighbourhood at night and see everyone's lights and trees in their windows? (We're lucky to live in a safe, pleasant and walkable part of London.)
I saw the London zoo has gone all-out this year for Christmas (I'm sure it has in years past and I just haven't noticed), probably trying to entice people to pay the eye-watering entrance fee by offering a Christmas "experience" on top of the regular zoo trip.
We are definitely middle class and surrounded by all of this, but I'm not big on social media so don't give a shit about keeping up with the Joneses. We do one or two small activities, visit a couple of local Christmas fairs, share some photos with close family and enjoy the holidays. I can understand the pressure to "create" holiday magic for kids via all these experiences. And if you enjoy them and can afford them - great! Have fun! But people shouldn't feel like they are necessary to have a good Christmas. Before paying for something, ask yourself why - is this something that genuinely brings you joy, or is it something that you feel you "have to" do to make Christmas "magical" for your children.
You know what makes Christmas magical for children? A lovely tree, presents and chocolate. Attention and affection from their family. And Christmas specials of their favourite cartoons!