My kids love the outdoors - so family camping trips were awesome for them.
If camping is your thing, a VRBO cabin can be a fun alternative. We've stayed in a cabins at Tahoe or Yellowstone. Kids loved both. Key to Yellowstone if finding some fun stuff to do that isn't just driving the park. We did Firehole River and they had a blast spending part of the day there. Or found a pull out picnic area at Yellowstone Lake, and they hiked around, splashed in the water, threw rocks, etc., for half of the day.
We did VRBO's outside of Zion and in Moab - these were both condos with swimming pools - kids loved hiking the parks part of the day and then hanging out at the pool or playing games in the condo part of the day.
Our family doesn't have to be going all of the time - and sometimes it's nice just to get out of the house and be away from everything hanging out and relaxing. I'm not a fan of spending all day playing video games, but a couple hours of Mario Party or Mario Kart part of the day can be fun. We even did a "read a thon" once on vacation - kids enjoy reading, we made sure they had a book they liked and all the treats they could eat. One of my wife's favorite activities.