You can argue this is clickbait, but it’s just the answer to your question!
I was using WhatsApp Web and noticed the system wouldn’t let me log in. Both WhatsApp and Instagram, owned by Facebook are down. Confirmed by countless people on Twitter. It appears that Facebook Messenger is also impacted by the outage.
This is an excellent time to download something better and more secure than WhatsApp, like Signal or Threema.