Everyone knows why the population in Wayfinder is low:
1) For new player coming in, there is hardly anyone around to group with. Bringing lfm up just shows emptiness across all level bracket, and when even high level raid lfm is non-existent, it becomes a tell-tale sign of the fate awaiting the new player.
2) For high levels, the lack of high level raid lfms for even the most common (such as Shroud) when he/she could have jumped to another server and easily find one do not provide much incentive to remain here.

So this becomes a vicious cycle, and it needs a drastic measure, one that requires all servers to chip in: allow players in Wayfinder server to be the only one to access lfms (especially raids) in all the other servers and be able to join them! This special capability can then be removed once Wayfinder population reach a stable size or only apply to early adopters.