There are unpressured bass in other places. It's just that most anglers either aren't willing to do the work to reach those places or have purchased boats that can't reach such places.
However, there are easily reached places that are also great. I had fishing sessions in Wisconsin that equal what I've enjoyed in Maine. The Mississippi River is a fish factory. I caught big bass on Lake Pepin, as well as big walleye, pike, crappie, bluegills, and white bass.
Lakes Superior and Michigan are great too.
Living in Minnesota, you sit right below northwestern Ontario, where I enjoyed the greatest fishing of my life. 100-bass-days-per-angler were common there, but those weren't lodge lakes. They were bush/backcountry lakes with portages and running whitewater rivers and crossing swamps, all challenges that many anglers avoid, but if you're willing to do the work, you can reach Nirvana. Up north, Pain = Gain.
I have observed other anglers catching far fewer bass than I catch while fishing the same water. It's not just where you fish, but having a knack for catching bass. You've heard my stories of being surrounded by other boats on the Mississippi and the Great Lakes when I was catching fish and they weren't. Not everyone has the knack and sidling up to a craft where fish are being boated is no guarantee that you too will catch 'em.