Can I Skip Asking Runtime Permissions On Marshmallow?

Now this is something very interesting for me, I know mostly about Runtime Permissions and i am well aware of why Runtime Permissions proposed? and How we can use it? but in this q

Solution 1:

are there any actual drawbacks of doing this?

Users may elect not to install your app, if they do not like granting all the permissions up front. Also, other behaviors that you might want based on higher targetSdkVersion values may be lost.

And what will happen to security which was main purpose of RunTimePermissions

Nothing. You still need all the <uses-permission> elements, and the user still has to agree to give you the permissions. However, that agreement occurs primarily at install time, not when the app is run. Bear in mind that users of Android 6.0+ devices still can revoke the dangerous-level permissions via the Settings app.

And is it really preferable to do this?

IMHO, no. Eventually, something is going to force your hand and require you to upgrade your targetSdkVersion. And, as I have noted, users may prefer to not install your app, going with some other app, one that does not ask for a lot of permissions at install time. Using a targetSdkVersion below 23 is a fine answer for apps that are no longer being maintained or for inexperienced developers.