Hey @Yash_Khatri,
Salesforce require the full scope if you want your application to have access to all the data accessible by the logged in user and it includes all other scopes. This scope does not include a refresh token so you need to include refresh_token as well. The offline_access scope whill allow the app to interact with the users data while the user is “offline” whatever that actually means 
The docs we follow are here: Help And Training Community
Did you find an issue with the full scope or is there a concern around using it?