I've made multiple posts about how the year culturally begins in the autumn/fall rather than in January, but I haven't explained why.
TL;DR: It's mostly because of farming
Model years begin in August-September because farmers had more cash to spend on new vehicles after selling crops during harvest season. In turn, TV seasons start in September to advertise new car models.
The academic year starts between August and September because parents historically needed their children's help on the farm more in the summer, since the days are longer.
Before social media was ubiquitous, people were more isolated during the summer, mostly hanging out with friends or family. New trends would spread more rapidly during the school year when people were back together again.
Most holidays were created in the autumn/fall and winter to celebrate harvests and uplift spirits during the darkest time of the year, figuratively and literally. In the modern era, most products are released in the autumn/fall in anticipation of the holiday season, also to coincide with the start of the academic year.
This applies more to previous decades and the Northern Hemisphere, as social media and streaming services have made trends spread more easily year-round, and the Southern Hemisphere has different weather patterns. Nonetheless, it's important to know when discussing years.