And even now, Zoho Mail doesn't offer Shared Mailboxes. (https://help.zoho.com/portal/en/community/topic/sharing-a-mailbox#2266000008316843)

I guess Zoho is possibly never gonna offer Shared Mailboxes? Even if we paid Zoho?

Collaborative Inbox for GMail: https://support.google.com/a/answer/167430?hl=en

Shared Mailbox for Outlook: https://support.office.com/en-us/article/Create-a-shared-mailbox-871a246d-3acd-4bba-948e-5de8be0544c9