It does, the GPU ends up bottle necking when you displace a lot of verts.
And no you would not see benefits between having tiles and having a single mesh if you always display the whole mesh. But, you would see benefits if you properly use LODs because the amount of displacement vertices from afar is drastically reduced.
another consideration is the fact that importing a 1760x1760 mesh with vertices every 1m is near impossible. The engine just doesn’t like large meshes with a lot of geometry to begin with.
If you are using this mesh as an ocean/water, the best way to go is tiling or in case you really are far away with the camera only using normals to fake the waves.
I cant really think of any other reason one would need to displace a single huge mesh in real time so…