Playing one game until completion

A friend of mine was surprised to find out that I switch what I'm playing every so often, and says I should be playing the same game until I complete it. That it's the best way to really experience the story and remember how to play and what you were doing

But I don't know about this. Being locked into one game for 40, 60, 100 hours or more. And when the controller is low power, does that mean I won't be playing today? And I'm single and live alone, which means I have to squeeze some video game time in the middle of all my other responsibilities.

Plus, what if I feel like playing Crono Trigger when I have a half finished Final Fantasy III/VI on my SNES Classic?

I have ADHD, which probably contributed to not staying locked into a long game until I complete it. But my friend has made some good points. And I do rarely finish a game, possibly because of this.

What do you think?