You are right; this new system could be helpful if it were implemented gradually and in a controlled manner.
As my own example, I have been with Fiverr for over 8 years, and for the most part, it's been pretty steady. However, last year I had my first baby, which had some impact on my performance on Fiverr. So, my last two years were spent dealing with pregnancy and then caring for an infant, which inevitably had some impact on my Fiverr profile. Even though I didn't receive too many cancellations or negative reviews, and earnings were not bad, I could feel a slowdown in activity on Fiverr. Gradually, I have picked up the pace, and things are finally on the right track. But now, out of nowhere come these success scores, which are calculated based on the last two years. And I am again evaluated with someone who started just a few months ago.
Rather than breaking and making these seller levels over and over again, it would have been better if Fiverr could incentivize the high performers or at least show us these private states much earlier so that we could tune our gigs and services accordingly.