How important is it to write a review (or Rate) a company, product or service to educate future employees, consumers and potential customers about it?

Yes, it's quite important and professional organisations follow this practise.

i do believ that it's part of my job to delever all kind of information for the new member in my team to get the best performance from them and also to grow our own sales target.

on the other hand, the main problem we or they'll be facing is the lack of knowladge the from the customers, so it's very important to give a full reviw about our products to them .

The query above already answered by its own paralysis. We are doing a review of our company, products or services only to educate both employees, consumers and potential consumers. With reviews, we will be able to identify and adjust what are needed to change or maintain. Then it will let us to be aware of.