Long post incoming.
Frankly, mock-up VSTs like East/West Symphonic Orchestra and Symphobia are so authentic and realistic that while they will never ever beat the realism of a real orchestra, they are far more practical and useful in today's world, and sound-wise can beat an orchestra quite easily, in the hands of a skilled producer. I'm saying this after having heard music that was made with VSTs and music that was played by a real orchestra. I've noticed that the VST music can often achieve so much more power and clarity than a real orchestra, since there are so many more factors to consider in a real orchestra.
Microphone positions, costs, the skill of each and every player, mistakes during performances, recording issues, amount of instruments you can incorporate, etc... when making digital orchestral music you can load up as many instruments as you want, and you have total control over the sound of each instrument. Often, with digital orchestral music I feel a lot more oomph in the drums, warmth in the strings, brightness in the woodwinds, and power in the brass. Let's not forget the limitations of each physical instrument and each player too. I've made piano solos that are impossible to play without three hands and they still sound great; I'd have more limitations if I were recording an actual pianist.
However, that doesn't mean music by an actual orchestra doesn't have its own merits. It's going to take a hell of a long time for computerised orchestras to even begin to match the expression of a real orchestra. In more expressive tracks, I think an actual orchestra will beat a computerised one, which is why Jazz, one of the most expressive genres out there, almost always sounds so much better with real instruments than computerised ones. Let's not forget that there are some things that digital orchestras can't replicate as well as the real thing either, like choir (provided the choir singers are actually good and the recording environment is adequate).
Lastly, pieces played by actual orchestras often have more personality to them. In the end, there's a limit to how many samples you can load for each instrument in orchestra VSTs. Taking a harp... in East/West there could be 8 samples (just throwing a number at random) for each note of the harp, which would be maybe 2 variations for each of 4 velocity layers (for example pianissimo, mezzo piano, mezzo forte and fortissimo). A real harp can produce an infinite amount of different sounds from one string, depending on how it's plucked, and that can make a big difference to the sound and personality of a piece.
So yeah, each have their own advantages and disadvantages, and each offer totally different experiences (in fact it's a silly dream of mine to get one of my orchestral tracks played by an actual orchestra one time in my life) but I think that computerised orchestras are far more practical and all-out better in most situations. This is coming from someone who never heard an orchestra live, though.