It's marketing madness and also actual changes, but not always both every year.
Let's keep things simple and stick with MINI. In North America the model year is determined when they do a production switchover, which is usually around March (I believe) of each year (for MINI), and after the switchover the new model year is used. So after March of 2022 MINI started building model year 2023 vehicles.
Sometimes they have no differences, sometimes they are completely different. The SE was officially introduced as a 2020 vehicle, but model year 2021 is identical in every way. Then in 2021 they introduced the 2022 LSI model (life cycle impulse), where the front end was changed and a bunch of new features like ACC and heated steering wheel were introduced. The 2023 model year cars are just now being delivered, but are essentially identical to 2022 models, with maybe some trim changes and deleted features due to supply chain issues.
What's going to be offered for model year 2024 (think March 2023 timeframe) is anyone's guess.