It may take some time depending on the number of files you have and the total size. You can use the "Email me when done" option to get notified once the archival completes. You can then download the created archive locally. Make sure to download it to your Google Drive shared folder or copy it there after download so it gets synced and backed up in the cloud.
One of the biggest advantages of using an online backup service is that it lets you access your files from anywhere. Most online backup providers let you view and download files from a web browser, but that should be the bare minimum. Many also include file-sharing options, the best of which even let you specify a password for access and an expiration date for the shared item.