Hi @himanshu_p!
Using AEM Assets as an Enterprise DAM, meaning the central point of access management, is a common pattern that we see at many of our customers. There is a vast number of use cases that can be covered, reaching from providing assets to multiple AEM Sites environments as well as other 3rd party systems, handling asset creation and creative collaboration and approval workflows to advance AI supported use cases leveraging e. g. Smart Tagging, Smart Cropping and more.
The topics mentioned in your post are usually worked on in a dedicated project as they cover way to much to answer in a community question. Also, the approach and requirements for an Enterprise DAM are often quite unique for each customer, so that a project should start with a discovery phase to identify the business requirements, required integrations with other systems for asset intake and delivery channels as well as collaboration structure for creative workflows.
For integration between AEM Sites and AEM Assets, you can check out the Connected Assets integration. For 3rd party systems, you might want to look at AEMs Asset Selector. These are two common options but depending on your setup and requirements, there might be other viable approaches.
Hope this helps!