If I delete a Connected App in salesforce which is associated with a hybrid Mobile App then will I be able to use the mobile app for login and API calls?
I am able to successfully use the Mobile App (Login/API's/CRUD) built with default generated bootconfig.json file(The one generated by SalesforceHybrid with no change). So what is the actual need of creating the Connected app and configuring its Consumer key and Callback url in app's bootconfig.json file?
The default cli generated app uses credentials for a test connected app for which you do not have any access controls. You should not be using these credentials beyond a simple test. It's essentially put there to jumpstart developers quickly by letting them focus on the capabilities of the SDK. A connected app is used to identify your application & org. It allows you to customize the auth behavior of the sdk and permits access the salesforce platform.
Here are some reasons why you should not use these credentials.
No Admin access to the connected app setting.
An admin of the connected app can revoke tokens anytime, essentially logging out your users.
Cannot customize the overall auth behavior for your app, e.g. usage of biometric auth, security policies, permissions & advanced auth.
You will be subjected to the rate-limiting & limitations of the demo app.
How to create a connected App?