Any Good Level Editor suggestion

Anyone know of a good level editor that makes asset/prefab management and laying out of props in game level a simple task of click/drag and drop and automatically place/align on surface?

I would consider having to use Unity + Asset Addon(eg. like Octave3D Octave3D-Level Design | Level Design | Unity Asset Store) and FBX export?

Any other alternatives? Maybe another addon/extension like Octave3D should be done for Playcanvas. Octave3D seems like a good product (from the reviews and vids) but comes at a cost. Guess nothing is free.

It’s extremely hard to go about populating/filling up this terrain world because it needs a fast way to quickily drop in assets/ move them around, yet align to raycasted surface on custom terrain meshes, etc.:

Coding an ingame editor seems counterproductive if there’s some off-the-shelf/(even prefably offline) solution out there that would work best in importing OBJ/FBX, then re-exporting out FBX scene. Then again, maybe having something ingame may be good as well