Ghosting as a strategy? Ageism? Who knows
These guys will not serve you up the full list of candidates. The reason? They ghost them. Totally unprofessional.
I understand that their clients are the employers, not the candidates. But if you contact them, they will never reply to you. The "something must be wrong with my WhatsApp" or "let me know your new number" when you haven't changed your phone number is not really all that credible.
It's not just me either, my friend had a conference call rearranged a number of times, and when the time for the call finally came up, Vested did not turn up. No apology, no excuse, just ghosted.
If you're looking to recruit, do not use this firm. They will not tell you about all the possible contacts in their network, because they either have no clue who is in their network (that's the charitable interpretation), or they know who they want to place with you, whether you want them or not.
Edit: Weirdly, with one review of 1 star, the average rating is 3.2? That is some strange maths.