Even the study behind Harman target very clearly noted that it is not optimal for everyone’s preferences, it’s just what the majority prefer.

So as it is, aiming for it is generally a safe bet for headphone manufacturers, and if you had to create one set of headphones to please the maximum number of people, Harman target it is. But of course, in reality we have to remember that people buying headphones are a diverse bunch, and if everyone else is aiming for Harman target, it actually might be better to aim for a different sound signature to please the people who would prefer some other tuning over Harman.

So, I wouldn’t be too worried about everything becoming the same, there are good market reasons to keep offerings more diverse even if Harman becomes more popular.

At the risk of sounding like a flowery hifi magazine reviewer, Clears are just really, really good headphones, while Utopia sounds like it has some magical special sauce going on with how "3D" it sounds with its imaging. Not big enough difference to justify the price difference for me, but still, the difference is immediately obvious.

Quite obviously you should only listen to your ears here. Harman target is a product of a preference study, and while it can be useful as a suggested starting point to try, trying to "learn" to like it is pointless if it just doesn't click with you. It's not supposed to click with everyone, and trying to push it as objective correct option for everyone is something that even the research never tried to suggest in any way, because unlike the worst internet zealots, the people behind the research actually understand what a preference study means.

As a comparison, imagine if I made a study about what pizza toppings are the most agreeable for the majority of people. Now, it would be useful info to know that pepperoni-tuna (or whatever) is what you should serve if you don't know your audiences preferences but wish to please as many as possible, but the idea that you'd have to order pepperoni-tuna personally yourself every time because it's "objectively proven to be the best pizza topping combo for human taste" is ridiculous.