1. In the UAE, where VoIP is illegal, the government was not able to selectively block voice traffic since it is indistinguishable from text traffic. So they had to ask WhatsApp to block voice functionality whenever a user is in the UAE.
2. If you lose your phone, you cannot recover your messages. Now, you may claim that they're just not providing a frontend option to do this, but would that make financial sense? You are potentially losing users who want their messages backed up so you can... falsely claim that you don't store messages?
3. Similar to 2), WhatsApp desktop cannot work without your phone being connected, again because that's the only way to access your messages.