Yes, WhatsApp is banned indeed in many countries, to different degrees. For instance, China, Syria, and North Korea do not allow WhatsApp on their internet. Whereas Brazil, Iran, and Cuba have temporary blocks on the app. So you need to use VPNs for accessing WhatsApp in all these countries until the ban goes away. Similarly, some other countries have not banned the app itself. But they have restricted WhatsApp voice and video calling features in the United Arab Emirates (UAE), Oman, and Qatar. In these countries, text messages will work fine, but you'll need a VPN to call anyone via WhatsApp.