0755 or rwx r-x r-x means that the owner of the file can write, while all other can only read. So your user (www-data) doesn’t seem to own the folder and therefore can’t write.
I ran - sudo chown -R www-data:www-data /var/www/vhosts/website-wi.com/httpdocs/piwik/
Which worked - Tested it with su www-data -s /bin/bash -c “/usr/bin/php7.0 /var/www/vhosts/website-wi.com/httpdocs/piwik/console core:archive --url=https://website-wi.com/piwik/”
BUT received this error when I went to PIWIK - The directory “/var/www/vhosts/website-wi.com/httpdocs/piwik/tmp/cache/tracker/” is not writable.
The hosting company and I did figure out why this was caused. I’m using Plesk with Linux and I have a different username in Plesk. Can I switch “www-data” to my plesk username or will that not work? If it will work would it look like - sudo chown -R myusername:myusername /var/www/vhosts/website-wi.com/httpdocs/piwik/ ?