I've owned many new cars over the last few years. I'll just say I used to spend 2-3 hours on most weekends cleaning and detailing the cars and now just wash them if they are filthy.
I use the 2 bucket method, a hose, a Mitt, and Meguiars ultimate wash wax. When I feel like it (about 1x a year) I'll put Klasse AIO and Klasse Sealant Glaze on. Are my cars clean all the time anymore? No. Do they still look good when I want them too or it's time to sell? Yes.
The car I traded in when I bought the truck I just keep tidy during the 3.5 years I owned it, and the day I was getting it appraised and trading in I did a vacuum, wash, wax, quick detail spray. Car looked great, dealer gave me top dollar.