Related topics regarding MEGA:
Personally haven’t looked at them in years. Doubt they meet our requirements.
They don’t exactly have the best reputation MEGA fixes critical flaws that allowed the decryption of user data
PG works based on recommendations from the community, so someone has to bring it forward to be evaluated and then a discussion starts on all the requirements

why it’s not in privacyguides list?
In addition to what @Fibonacci succinctly noted above, I encourage you to at least look at the appropriate criteria before asking a question like this.