I am planning to move email to iCloud+.

- Provides custom domain support.

- Is cheap ($1 for 3 email addresses).

- Has email web interface and imap access.

- Seems to support contacts and calendar sync via carddav, caldav - standard stuff I can sync my other devices with.

- Apple is reputable enough with security.

Drawbacks:

- No standard two-factor authentication like Google, needs an iPhone/mac for two-factor.

- Migrating Google Photos/shared will be a pain in the ass.