CoopsII wrote:Someone else would've. You cannae change the laws of physics...

Quite true - Rudd had already experimented with a ground effect car at BRM in 1969 (only for Surtees to intervene and force Owen to cancel the project), whilst Wright intended the aerofoil shaped fuel tanks on the sides of the March 701 to also work in ground effect (although they never really worked as intended because of excessive turbulence from the front wheels). Both of those men were quite influential in Lotus's development of the 78 - Wright was in charge of the aerodynamics research team that lead that project, whilst Rudd was responsible for developing the chassis of the 78 and 79 to accommodate the tunnels. Now, with Rudd having head hunted Wright specifically for his own consultancy, it is plausible that, had Rudd ended up elsewhere, Wright probably would have followed, and they both might have drawn on their earlier research at whatever team they ended up at to develop a ground effect car - Rudd, after all, kept the wind tunnel mode that he'd made whilst at BRM in 1969 on public display in his office, so he could easily have replicated those results elsewhere.
It's also worth noting that some other outfits were, unintentionally, taking advantage of ground effects too, albeit not in the systematic manner in which Lotus went about it. Forghieri accidentally took advantage of ground effects with the 312T series - he noted that the use of the wider, lower chassis the 312T had produced better downforce figures in the wind tunnel, but initially he attributed that to improved airflow to the rear wing rather than the fact that the underbody was starting to act in ground effect.
Murray also inadvertently took advantage of ground effects with the front wings of the BT44 and BT45 - he experimented with air dams and skirts on the BT44, and he later realised that the BT45C's front wing was also acting in ground effect too (which was why Lauda repeatedly complained of chronic oversteer, because the aero balance was far too far forward thanks to the increased efficiency of the front wing). Murray worked out very quickly what was going on once he caught a glimpse of the underbody of the 79, so it is plausible that he might have had that stroke of genius instead and been the one who kick started ground effects instead.