The fast road is fine for getting somewhere. The long way home is how you find out what is on the way.
On the last trip we added forty minutes and ended up at a viewpoint that was not on any list. We had it to ourselves for an hour.
I keep a small bag in the car with water, a jacket and a flask, so I can say yes when the road looks too good to skip.
Leave early, take the turn you have never taken, and let the day run a little longer.