I used to not give this much thought. Then a stint of voluntary work brought home to me that there really are a lot of people for whom Christmas is a very sad, lonely or depressing and stressful time of year. People who have to steel themselves for the annual onslaught of Christmas music, people talking about the family and friends they are going to spend the day with, the toys they've bought their children - people who have no money to spend, or no one to spend it on, or no parties to go to, or no one to spend the day with.
For those people December is a month that comes riddled with aloneness, anxiety, sadness and even shame.
Forcing all that on them earlier and earlier just makes it more difficult for them even if "we've all had colds/are fed up of covid, and need all the twinkly lights to cheer us up". (obviously a terminal illness is a total exception).
So yes people are entitled to put their trees and garden lights up anytime they like. But do spare a thought for all the people out there for whom Christmas is not a time to look forward to. And not because they're grinches and scrooges. But because they have difficulties and profound sadnesses in their lives that those of us more fortunate don't have to deal with every Christmas.
Those people don't exp Christmas to stop just for them, but they quietly dread the ever expanding time that now seems to encompass the Christmas season.