Disclaimer: I have been a user of almost every email provider mentioned below, and I am not affiliated with any of them.
You can read Forward Email’s comparison with many providers here: https://forwardemail.net/en/blog/forward-email-vs-mailbox-org-email-service-comparison , by substituting mailbox.org with others on their list.
In short, Forward Email has some wrong information. They attempt to achieve full score in every security test and prove they are superior to their competitors with scores. I don’t know what is driving Forward Email towards being a pupil, and it seems like many privacy seekers get trapped into how high they score in the Internet.nl tests.