It is like a statement to your company’s stakeholders, creditors, employees, and others that your established business operates in a framework. And this framework is used to achieve all your objectives, be it customer satisfaction, production objectives or environmental objectives, etc. And as this certification is not internal but external, this keeps in check the credibility of the certification as well.
There’s a request of many public sector tenders, where the ISO certification is a pre-requisite before allotment. In that case, it would give you an edge over the competitors who don’t have this certificate and would enhance the chances of your business getting that tender.