For a simple and effective Gmail backup, I would recommend using the SysTools Gmail Backup Tool instead of relying only on manual downloads.
It allows users to back up Gmail emails and attachments to a computer in commonly used formats such as PST, MBOX, EML, and MSG, depending on the required use case. The tool can preserve the original mailbox folder structure and is useful for archiving emails, creating a local copy for disaster recovery, or preparing Gmail data for migration to another email platform. It also supports backing up multiple Gmail accounts, applying date-range filters, and downloading selected mailbox folders, which can make the process much more manageable when dealing with a large Gmail account.
For anyone looking for a straightforward way to keep an offline copy of important Gmail data, SysTools Gmail Backup Tool is worth considering.