If you are willing to turn on other types of sync (which gonna make the game stutters some times) then yes it's worth it
1440p with g sync is the optimal couple for this card IMHO
The monitor not having g sync shouldn’t be a problem because most game have a version of it built in to the engine anyway and if your monitor is 144hz it will only refresh at 144hz max which will reduce the tearing because the hardware actually supports the FPS
G-Sync is not important when you're hitting that high of a frame rate anyways. So yes totally worth it, the jump in hz is VERY noticeable, without g sync