Self Service has been a trend for many users. Allowing your customers to see and act on their ‘data’. See the status of their order, change their address or search a knowledge base are just some examples of where portals can be used. While GDPR and transparency are becoming more and more important, portals can also be a way to show customers what data of them you have on record.
While SharePoint and Portals have been synonyms for a long time, current technology enables us to move away from SharePoint as a front-end tool or UI to your employees. Not something many would regret. Nowadays we use SharePoint more and more to ‘just’ store documents and use tools like Power Apps and Power Apps Portal to build the UI.