What is the difference between Vive and a collective pension?

In short:

• Collective (2nd pillar): shared risks, sometimes guarantees, but mandatory participation, more complex administration and less flexibility. Changes require consent.
• Vive (3rd pillar): optional, quick to set up, flexible in who takes part and how much you contribute, with low administrative burden. The participant carries the investment risk and there are no guarantees.

So it is not better or worse, but a different trade-off between certainty and flexibility. Read collective versus individual pension.