@Jason Lambert yeah this is the right question to ask and honestly the answer is pretty straightforward once you understand what's driving that 50km number.
The 50km figure is the drone-to-drone spec, meaning both modules are airborne with no ground reflections interfering. At altitude you essentially have clean line-of-sight by definition, so that's the best-case scenario the module is capable of. The ground-to-ground spec drops to 5km, and a big chunk of that difference comes down to exactly what you're describing — terrain, vegetation, buildings all eating into your link budget.
That said, "line of sight" in RF doesn't mean perfectly unobstructed like a laser. The module's receiver sensitivity is what's doing the heavy lifting here, and a well-designed front-end can punch through light foliage or handle mild terrain obstruction better than a commodity BLE chip. Dense urban canyons or solid hills between you and the other module are a different story — those will hurt.
Practically speaking, if you're flying drones you'll be close to that upper end of the range. Ground deployments in open fields will do well. If you're trying to punch through a forest or around a building, expect meaningful range reduction and plan your deployment accordingly.
