Yes, when it's wet and water is available for breeding. When they're not in the water breeding, rain or water on leafs could provide moisture. So, I suppose an automatic misting system could suffice. You do have a point about bio-active tanks. A filtered water section won't need more than weekly maintenance. The problem is here that it is small to medium frogs that do best in bio-active enclosures unless the keeper is willing to go all out and purchase custom or large enclosures for larger frogs. I suppose gray tree frogs, native toads or tomato frogs would be nice in a live planted enclosure with a sectioned and filtered water section. All of this will require more space, money and thought/research into it.
Anyway, doesn't solve the issue with food. Most frogs, especially small to medium ones suited to bio-active tanks, that I'm aware of or have kept and other than the gannets (e.g. Whites, pixies and pacmans) need food daily or every other day in small amounts. Letting them gorge on too much food at once to satisfy them for days could cause digestive upsets and when food is plentiful in a captive setting they will eat so much. Dumping loads of crickets in the tank to do for days is not a good way to deliver food. This would be fine every so often if you go on holiday, but a monthly basis the risks are greater. Also insects might eat plants and grow in a larger terrarium and could harm frogs. Supplementation will be lost after few hours of being in the tank. Gut load could be left in the terrarium but this itself needs changed every other day, especially in a warm and or humid environment. It could go off and cause problems.