I see the argument of road relevance thrown around a lot in discussions such as this one. What I find amusing about this argument is that there is probably an incredibly small percentage of Motor Racing enthusiasts who actually care about the road relevance of the technology that goes into F1/LMP cars. This is more of a marketing gimmick that is used by manufacturers and it seems to have worked.
The automobile and motor racing have matured way past the point where you will have engineering and design breakthroughs that will have a noticeable impact on road vehicles. Don't get me wrong, it will still happen once in a blue moon, but it is no longer a valid justification.
F1 and WEC had stopped "pushing the boundaries" of engineering quite some time ago. Now it's just become a calculative and iterative engineering exercise. The real innovation happens outside of these motorsports.
I guess this is a bit of an off topic rant, and kind of irrelevant to the discussion