Hey Mrdamasajaga,
It should only be writable by the owner/user (755) of the PHP process. The wp-snapshots is not part of the archival process as its filtered at build time. When the package is created it needs to write the database.sql file to the root of your site for later use in the archive. Also on the installer in order for PHP to unzip the archive.zip and update your wp-config.php it has to have write permissions.
This is also true of even core WP code which writes to files such as the .htaccess which is in your root when saving permalink settings and a general recommendation by WP:
https://codex.www.ads-software.com/Hardening_WordPress
The root WordPress directory: all files should be writable only by your user account, except .htaccess if you want WordPress to automatically generate rewrite rules for you.
If your going above and beyond the WP settings then the only way to get around the issue would be to allot for a new path (i.e. wp-content) for the database.sql This currently is not supported, but may be a possibility. You are the first person to ask for a different route…