I agree that establishing a time frame for calculating success scores is essential. Evaluating a seller's performance based on their work from 10 years ago does not accurately reflect their current abilities and performance levels. The system should disregard orders that are more than 2 years old.
Introducing time frames of 3 months, 1 year, and 2 years for score calculations, and selecting the best score from these periods, could be a more equitable approach.
The primary issue with the new system is its complete lack of transparency. Improving client satisfaction becomes a challenge when the factors influencing this metric remain unknown. Furthermore, the concept of private feedback is inherently problematic, although that is a discussion for another time. It is well-documented that people are more inclined to leave negative feedback. Putting so much weight into this is bad for everyone, including buyers, in the long run.