Most people don't do their own maintenance for several reasons.
1. lack of time. Even some of my friends who used to DIY a lot of stuff simply can't anymore due to work schedules, young kids, etc.
2. lack of tools
3. modern cars are not as easy to work on
I cannot agree with these reasons.
1. Time is money. Find it. Paying $100 for an oil change one can perform at home for under 30 bucks is ludicrous. So folks have the time to drop off their vehicles and/or wait at a mechanic's shop? And they have time to sit on their butts and watch Netflix? I don't swallow it.
2. True at first, but tools are an investment accumulated over a man's life. If need be, forego the monthly streaming services and buy a wrench...
3. Probably more of an intimidation factor. Strip it all back and there's still a four-stroke engine under all the plastic. Get a factory service manual, check You Tube for some excellent how-to videos, and get your hands dirty. It's not that hard for most cars.