Depends on what your goals are. Going for a ride is a lot differemt than going out and drilling on your bike. Same with a stationary trainer. You can just do some time on it or you can do specific drills designed to achieve goals. Recreational riding isn't about aveage speed, miles, time, or intensity, it's about fun. Training on the bike whether on the road or stationary isn't about miles and average speed. It's about time and intensity. You can train without regard to time and intensity but you will not be training effectively and efficiently.
If you don't care about that then it doesn't matter. Do what ever you want to and enjoy. You will likely see some gradual improvement.