Good question.
The answer is that you don't need any of those VST's to make good music.
However, with the range of effects the VST's in this pack cover, producers can achieve an even wider amount of sounds than instruments, percussion and the voice alone can provide.
One example is to use reverb to 'place' the sound for the listener. A large strong reverb will sound like a cavern or cathedral hall, whereas a short minute of reverb on drums will make them more lively.
The delay unit is another example of a useful plugin. Adding echos that trail off in volume would require lots of copying and pasting and volume automation without using a delay plugin.
You don't need to get the latest version of each VST, the ones included in the pack will do the job nicely. But if you're a pedant, then obviously grab the latest ones..!
