The "wp db export" command is failing with error message:
mysqldump: Error: 'Access denied; you need (at least one of) the PROCESS privilege(s) for this operation' when trying to dump tablespaces
The "wp db export" command executes mysqldump using the DB_USER and DB_PASSWORD variables taken from the wp-config.php file. Generally speaking, this user may not have the specified privileges, and thus would be unable to perform the dump.
To avoid this issue: Use the --dbuser and --dbpass options to specify the username(cPanel account username), and then prompt for the password. More information on this WordPress tool is found here: https://developer.wordpress.org/cli/commands/db/export/