Has Hyundai Become The Benchmark For Non Premium Automakers?

Yes and No. But they are close to the top.

Is Toyota's line up better? No.
Is Nissan's line up better? Maybe.
Is Honda's line up better? No.
Is Mazda's line up better? No.
Is Mistu's line up better? No.
is Subaru's line up better? Yes.

Keep in mind, especially with small cars, Nissan is now following Honda who is following Toyota. Keep it dull, uneventful, and bland enough and you can still get your hords to the dealerships. To me at least two of these companies now sell NEW rental cars.

I'm pretty sure Nissan is not following Honda or Toyota. They developed a 350Z and G35 then went on to make the 370Z, G37 and GT-R. All the time Honda was removing all sports cars from their lineup. And Toyota didn't have anything since the Supra left the market (even the IS was toned down from its Altezza roots and the SC was changed into a boulevard cruiser). Now they made the Leaf (which if it copys anyone, it would be GM). Neither Toyota nor Honda has brought a plug-in to market yet.

So in my view at least, they are walking entirly different automotive paths.

Now Nissan needs to be afraid of Hyundai. Becasue the Genesis lineup is a direct threat to what they develop. Once they put in the new engines to the Gensis coupe and maybe a design change or two. They could be nailed up against a wall. Until Toyota brings the FT86 to the market they aren't even in the competition with Nissan and Hyundai...and Subaru (should thow them in for good measure).

And Honda...Ha... Honda (excuse my language) needs to get its head out of its ass.

They only have been this good for one model generation, they have years to go and have to still prove their shaky reliability to earn that tittle.

LOL, no!

Being the benchmark in this class is about engineering a car to check as many features boxes as it can, for as little money as possible, without impairing reliability or baseline safety, while still making a sustainable profit. No small feat and maybe they're on the right track, but I agree with upwards that time will determine whether they've earned the title. If they're checking off the boxes, but are not making a profit, you bet they'll either raise the prices or begin further cost-cutting measures and you only have to look at Toyota to see what happens when you pursue the latter course.

They are still the somewhat new entry to the mainstream auto builders and I would say the jury is still out as far as rust is concerned . Modern day automakers did not slow down the corrosion problems on cars and trucks overnight .Years ago on many US and I will say Aisian auto built cars rust was pretty well set in when the car was five years old . This has changed with many technological improvements that slowly evolved . Unless the Korean auto makesr have pirated all this tecnology , they will will be dealing with premature rust and corrosion issues

Why not yes? If this question had been asked 5 years ago no one would have cared. But the fact is that the old norms no longer apply in the hierarchy of tried and true automotive brands.

Gen Xers and Ys are no longer interested in mere reliability or safety as that is expected in all modern cars. Hyundai has been appealing to this group by advancements in design, fuel efficient engines and powertrain technologies.

The market place confirms this fact.

I know one thing, Honda, Toyota and Nissan needs to stop acting like Hyundai is not a threat.

Probably. They've been marked as the ones to watch for years now and it's coming to fruition. Top reliability, top features, top safety marks, and now top resale values as well.