>>27361461
>It's useful, but it has set entrances into it.
It mostly has set exits, in that there are tunnels that lead somewhere. But the real-world entrances can move, as evidenced by them being mounted on Craftworlds, starships, and even the superheavy Storm Serpent that is basically a Scorpion with a Webway gate. Also, even if the gate is fixed on a planetary surface, the planet itself moves through space, doesn't it?
Then there's the fact that the Eldar are able to create temporary capillaries of the Webway that align with small, temporary portals, such as those carried by the Harlequins, Dark Eldar, or Ulthwe Strike Forces in EoT campaign. The creation of such a temporary tunnel is described in Path of the Warrior, when the Eldar assault some world.