I think there is value in marketing yourself as high level Wix agency. It’s set the expectation that you are someone with experience.
On top of that client are more likely to pay a premium price to work with a Platinium partner rather than a Silver partner
Both might do fine work but chances are that Platinium has more business experience and will be able to handle bigger project rather than a fresh partner who only started a few weeks ago hence the premium price.
Moreover, thanks to badges, partners are going to advertise their level on their website, emails (why wouldn’t they) and the naming will only bring confusion to client IMO.