Okay pump the brakes Rojo. Because you are far too surface level here.
1) We are talking about vastly different product, used on vastly different surfaces for one. When you want to talk about the performance benefit of "energy return" it comes down to deflection of material under the foot and resilience (ability to return to its original shape). And the only material in these products that does this is the foam. The thicknesses of foam in track spikes are obviously different to those in road racing shoes (actual underfoot the difference is almost 2.5X - don't just look at the sidewall) and does not allow enough compression/deflection to create the same benefit. The most important elastic/energy return component in track running is still the track surface.
2) Wavelight itself is just the gateway or enabler to the ultimate performance benefit - even paced running. Wavelight isn't the performance enhancer - even paced running is. Again you can't compare the marathon and the track - it's far easier to run even paced at slower speeds, in your aerobic energy system. The marathon doesn't need wavelight as much as the track does. And also let's not act like the breaking 2 attempts where there essentially was a mobile wavelight helping Kipchoge, didn't help him understand his boundaries and pace judgement better for actual legit 'thons. And let's also not act like the motorbike which essentially rides in front of these guys with the running clock emblazoned on it doesn't act as an unofficial pacemaker (I'll let you in on a secret the driver knows exactly how fast to go based on what the lead guys want to run).
Bottom line, wavelight means a hell of a lot more to track than it does the marathon where the footwear is far more important.
3) No wavelight that mattered in the SC record? What race did you watch? Girma passes the front of the blue light at around 3min50-55 of that race. You don't think that the opening 50% of that race was crucial to what happened in the final 50% of that race? What if the pacemaker - instead of going through 400m in an even 63 seconds because he's right on the light, goes through in 61 because he's excited he's pacing a WR attempt. Or if he gets too conservative and runs a 64.5 and all of a sudden in both scenarios the pace has to fluctuate to get back on schedule? The two pacemakers who give him just over 3 out of 7.5 laps of perfect even pacing, do so because of WL. Before Girma passes the front of the blue light and moves away he is visibly looking down at it. When he does go past you don't think he is benefitting mentally from not seeing that light anymore? Every step he's taking he knows he's ahead of schedule - no benefit there?
4) This final comment - "people who act likes the shoes don't matter who haven't worn the new shoes". Firstly nobody is saying the shoes (spikes) don't matter - the question is how and to what degree, and more importantly how so in comparison to the other massive advancement we have on the track now (WL). In a way it kind of sucks that inadvertently, both of these performance enhancers came at almost exactly the same time so we didn't see a Cheptegei 5/10k attempt with only new spikes or vice versa with WL.
You can think the spikes are more important - I disagree. I worked first hand on and around these exact products for many years and I can tell you for a fact a net positive benefit is hard to quantify because we couldn't apply the same conditional testing logic we did in road product (mostly due to the surface and foam thickness differences) and we landed on it mostly being a cushioning benefit that helped athletes with short and long term cumulative fatigue (as Willis alluded to). That benefit was and is very athlete to athlete dependant.
The performance enhancement "pie chart" of total benefit?
At pro level (which is what we are discussing here when you are talking the Marathon WR, Girma, the current state of the 1500 etc etc)
Even paced running fuelled by Wavelight - 80%
"Super" spikes 20%