The primary reason we use enqueue scrips is because WordPress will properly manage all the requests. For example, if two different plugins are using a certain third party library, WordPress will make sure that the script is only loaded once. It will also do a good job of handeling multiple version of the same script.
Lastly, you will also be able to conditionally load scripts. i.e. admin page scripts can be set to only load when inside the admin.
If you import your scripts and bypass this feature, you can no longer take advantage of this ability of WordPress to optimize the loading of scripts by multiple authors.
I hope that helps.