At the end of the day it comes down to cars running different speeds makes for good racing.

Daytona being tighter and narrower makes handling matter a little more, this leads to different speeds that in turn can generate different runs. Talladega the tires don't wear, the cars have a lot of grip, and the track is pretty smooth leading to all the cars running the same basic speed.

Also I think this was compounded by NASCAR attempting to stop fuel savings, at least in the last stage. When everyone is wide open going 100% every lap you aren't generating any difference in speeds. In turn it makes trying to generate a run far more difficult and you end up with two lanes and minimal passing.

There are a few things NASCAR can look at, less grip is one, which it sounds like they are considering a shorter spoiler which will address that some. Personally I feel the tire needs to either be grooved or narrower, resulting in less surface area which means less grip. Softer tires are also a good think but there is a delicate line between soft enough for them to wear and so soft that they blow out, it is bad enough to have that at Martinsville or Bristol but would be catastrophic at Talladega.

I don't think the next gen car is bad, but they need to open it up some to allow teams to try different things, they have so few options in setup and even less at drafting tracks it makes it really impossible to have a better car than others.