Vue, for what it is, is a good renderer, it's just way too finicky to get near -photorealism results though IMHO.
But then, Maxwell can do photorealism but is an utter PAIN to work with the materials and is not capable of any editing beyond basics like scaling.

Vue's renderer is better now than it was, but Vray etc usually cost an additional $500+ and more bucks. And you still need an app to run them in, so, you have to buy Max, Lightwave etc on top AND if you want pay for better maintenance cause they offer that service too..

So you're being very biased in your appraisal. (though I agree that Xstream price is a bloody RIP OFF!)

Could Vue be better? yes it sure could. But you're taking about a difference, a REAL difference in costs of a minimum of $1500 (FryRender and Lightwave) to $6000 (Maya and Maxwell)
Then add in optional Maintenance packages for them too, which iirc run from $300 to $800 for standard contracts.
Remember, I bought maxwell in Apha so it was a hell of a lot cheaper!

eventually all render engines will go to unbiased, but it wil take a while, and anyway, it's not always desired, I don't want a lot of my work to be photorealistic, it's meant to be a specific artistic style, not realism! :)

IMHO, Vue does need work to improve the render engine UI etc to help new users, hell, even me!
See Chipp's interior lighting pack, I've had a hell of a trouble getting things to look anything close to what he did, lol.

one of my Maxwell renders, from Rhino, of model I was working on, test shot

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