I agree that road blockage should be added accordingly, but there are third-party services that set appropriate tags for blockages/constructions/etc. such as Here, TomTom, INRIX, etc.

Please be mindful that OpenStreetMap is database, not service on top of the base layer. To make it easier to understand - OSM doesn't have routing algorithm, but it uses 3 other algorithms, it doesn't even have search engine, but uses Nominatim. So to make it crystal clear - it is database which should have good basic information (for example whole road network and house numbers), and on top of that third parties are building services.