DCS is a wonderful game/tool but when it comes to present-day warfare, it’s not all that good a source for analysis. Its radar modelling is simplistic at best, though some modules (the mirage 2000 for example) have very detailed radar modelling. There’s no account for aspect afaik however, and jamming is modelled very simplistic indeed.
So when it comes to post-F-22 era air-to-air warfare, DCS is not a good source.
So what is it good at? Well, most things short of that. It models aircraft and flight dynamics very well. It has a damage model and fairly detailed modelling of IR sensors. That means it does allow you to see how an A-10C compares to a Su-25 when it comes to providing CAS over a hot frontline (spoiler: both will take hits and therefore not murder to their full potential, but the A-10 will more likely make it home)
A better game/analysis tool might be CMANO. It doesn’t have the first person experience, nor does it have those sweet, sweet graphics, but what it does have is an extensive open source database of sensors, platforms, etc. Very detailed modelling of sensors, jamming, datalinks and informational warfare. It has opened my eyes to the worth of the F-35 thoroughly.
Radar resolution is directly proportional to wavelength. A millimetre radar will make a fairly detailed picture, detailed enough to tell an APC from a schoolbus. Take it to centimeter size and you get just enough to tell a MiG-29 from a Boeing 737 when seen head-on at a certain range. But at meter lengths, you get just enough information to know something’s out there, but not enough resolution to guide a missile.
I don’t see some magical radar technology flat out “defeating” stealth tech. What will happen is that the ranges at which you can reliably consider yourself unseen will get longer. Bigger threat circles so to say. But a far smaller threat circle to you in your F-35 than yours is to major Cuntovski in his Su-27.
Now if Cuntovski by some unimaginable miracle gets his hands on a Su-57 that performs to brochure level (axaxaxa!) it’s autocannons at dawn, with dircm taking care of the heat seekers. And that’s when the fact that the F-35 is tiny and driven by a creative and scared and highly trained human being is going to tell.