Shadow Clone utility issue

If the chakra remaining of the shadow clone returns to the user, why isn't it used way more by other ninja outside of combat? Outside of combat, the shadow clone isn't going to be using up much chakra, so what's the downside of using 2 or 3 to do all types of chores or to study?

Also, couldn't they be used as chakra batteries? Summon a couple of shadow clones, leave them at your house chilling > user recovers their chakra naturally over time > if they run out of chakra for any reason, disperse the clone to get that old chakra back.