People like to get their seasonal pictures perfect for the social media hits.
You might not agree, and I don't, you might think we are circling the drain of civilisation, and I could be persuaded, but it's a fact of modern life.
If you post a picture of your beautiful autumnal decorations and are one of the first you will get more hits, hence more money/exposure/build the brand. It works. Otherwise it wouldn't be so big. And by getting the big hitters to decorate their houses for autumn, halloween, advent, christmas, valentines, mothers day, easter, fathers day, probably summer perfect picnics, you feed the consumerism monster.
Or you can look at things from a different angle, a greater number of people, especially younger people, do not have as much disposable cash. Going out is expensive nowadays, live venues have closed so what is still open is busy. People spend a bit less on decorating their houses because they are in them a lot more than ever. Youngers take photos of their surroundings and look at photos of others because that is part of their entertainment. It might not be very healthy, or maybe it is, who knows, I am not a young adult in this current modern world.
Some people have difficult lives daily, they work hard, like many do, but get paid just enough to squeak by, they have to say no to treats for their children all the time or days out, or new shoes. So they do try to make Christmas different, better, a few days to enjoy.
You can swiftly walk past Christmas aisles, or avoid seasonal displays. But tutting and judging others doing things different is sort of the total opposite of the season of goodwill anyway. Or do people have goodwill ONLY at Christmas, goodwill is not available for any of the other days of the year.