Keep doing what you are doing.
Meshes perform way better than landscapes.
Using a landscape only brings performance down and introduces a bunch of problems.
The landscape benefits are few. If any.
First.
You get a max of 1vert every meter at default settings.
This means that most terrain detail is inexistent compared to your mesh.
(Sure, you can compress the landscape, to get verts up to each CM, but then the landscape size is something like 8m instead of 8km.)
Second.
You can paint landscape layers, and grass via material.
Sure, that is convenient, but it also comes at a huge performance cost for what it is.
(You can paint foliage on a static mesh. Grass is foliage. So you can do that instead.)
Third
You can have more layers on the landscape than you can on a mesh via vertex paint - BUT.
You can also produce alpha masks in another program on the mesh and export them packed for usage in a material. Which will by far outperform the landscape render time.
Fourth.
Landscapes cannot be sculpted at runtime in game - just in case anyone may erroneusly think they can because it is possible within the level viewport.
The functionality is editor only. Therefore, it makes no difference between using the landscape or using a mesh for this purpose. (Procedural mesh generation is possible with the procedural mesh component).
Fifth.
Unlike what you can do with meshes in other programs, the landscape is by default flat.
To render an earth like surface, you need a geo-targeted heightmap. Normally DTMs are not geotargeted, so it’s an extra required step to take (Which is also counterintuitive when detailing with portions of a zone that’s between tile borders? Meaning you need to pick one of the tiles and be ok with the distortion the format brings into the mix of the tiles to have something with somewhat “correct” distances between landscape features marching earth - whereas, if you build the same size mesh or combo of several meshes in a 3d program you can parse it for spherical approximation so distances match better without extra distortion.)
Sixth.
And maybe the only benefit to the landscape system.
Is that it works with the water thing epic produced (Which I have no idea why anyone savvy enough would ever even consider using, but that’s a different topic).