Basically every world is quite inactive for around half (or even more) of its lifetime, so why don't we make "expedition world" like Salem? https://salemthegame.wiki/page/Expedition
(1)Expedition world would only last for one or two months
(2)It will start when the regular world become inactive, like around 6 months after resets
(3)Regular world can be maintained, or maybe paused
(4)Participants, Players who achieved some set goals and top rankers will get prize, probably special hats
Pros
(1)There will be less inactive months
(2)Developers can experiment the game mechanics before trying that for the regular world
(3)Players can be more involved in new things, such as pvp for regularly non-pvp players.