Encrypted traffic
In the early days of the internet, internet traffic was mostly text-based, so everyone sniffing over the network could see exactly what was being sent over it. This was extremely unsecure and people could not send sensitive information such as passwords over the network. Since then, the internet has come a long way. Now, most internet traffic, except for some really old websites, is secure and uses encryption. This means that even if you can see the traffic, you will not be able to read it since it is encrypted. If you see the https
tag on a website's URL, this means that the network traffic is encrypted and can't be read over the wire. There are tools that can be used to decrypt this traffic.