I dare say more people play Mario kart than iracing but that does not mean iracing should take features from MK.
But in both games you can change your kart/car, and in both the tweaks are instant. You don't have to wait a few days for the mechanics to order the parts, install them and test them. Because that isn't niche gameplay, it isn't elite, it isnt hardcore, it isn't interesting. ED doesnt have that either, because it would be
stupid. iRacing sets itself apart with its driving model and such. All the parts that set it apart have direct gameplay consequences. Some like it, some don't. Same with ED's flight model, module damage system, power management and so forth. Far more convoluted than, say, NMS, but that is
fine.
The issue with ED is that some of the 'realistic' bits are neither realistic nor lead to any sort of gameplay. There is nothing wrong with going for a less casual approach, but at any point the question should always be:"what is the intended fun here?". That fun may only appeal to a minority, that itself is not a problem. But if you go back to the DDF, what we currently have was not what anyone envisioned or wanted. Because what we currently have is daft. Tons of interesting, niche, dangerous, challenging et cetera ideas were pitched for long-distance travel. I'm all for
that.
But we have none of that. And anyone who has a reasonable normal set of brains would readily concede that what we have now is not 'quintessential Elite', not what the original discssions were about, not what anyone at the time pitched as interesting or fun, not challenging, not realistic. It is just not fun in any way you look at it.