Negative reviews and agency on Upwork?

Question

Upwork

I would like to clarify, maybe someone in the know:
1) When a freelancer is added to the agency and the work is done (it doesn’t matter if he is exclusive or not), if the work is done well and the review is good, then the rating grows for both the agency and all freelancers, or the agency and done the job? And the same moment on a negative review, will the rating deteriorate for everyone?
2) Based on the first, if everyone spoils, then it’s risky to take each freelancer, because he can simply score, or inadequate, or inadequate customer, etc. , and of course a freelancer?
I saw the answer from Puma Thailand in another question, but did not understand a bit
"who worked and gets feedback, who didn't work doesn't get it", but the agency as such does not have a personal JSS, common to all employees.
Thanks