It's true that once you see everything to see, there's not much attracting anymore as if it comes to survival aspects there are other games that do it better, for roleplay aspect there are other games that does it better, for exploration it's the same... etc...
Additionally the interest of your world is very linked to what random worldgen will actually produce
The sandbox nature of adventure mode is a bit too limited in current version in term of the possibilities (and the bugs and serious performance issues that may make some otherwise interesting feature completely broken or not working as they should very likely does not help as it limit seriously your fun) to live up to what you expect from reading other people "romanced" posts about their adventures.
Hopefully once some of the
planned stuff for adventure mode finally get into the game, things will change and the adventure mode will live more up to its potential.
Meanwhile out of taking a break out of the adventure mode while waiting for it to be improved, i agree with giving a try to a peasant instead of a hero/demigod start, sure your stats/skills will be really low and due to how stats/skills max are limited by their default value a long lived peasant character will still suck, but it's important to notice that npc have different reactions to your peasant character in comparison to your hero/demigod ones leading to a slightly more "lively" world.
And games threats are actually threats when you're using a peasant start instead of just yet another easy "challenge" , avoiding the boring routine feeling to kick in too early.