Obviously, the conventional wisdom is that modern Android does this so well for us that overriding what happens automatically is counterproductive.
Allowing for a moment that modern Android is all it's cracked up to be (obviously it's not), even if that were the case, there are some apps I use only occasionally. I've always felt that clearing them, and clearing their caches in a lot of cases, was beneficial. Why use storage and RAM resources on an app I use, say, once a week, or a couple of times a month?
Also, I've found with the G4 (and I don't know if this is the G4 or Lollipop) that finding rogue apps is even more difficult than before. It seems you often have to deduce more than in the past. It's never been clear as day (unless you had a rooted phone and wakelocks available, perhaps), but more muddy now.
Just some stream of consciousness rambling.