In 2020, TLS 1.0 and TLS 1.1 are retired by all major browsers. And some applications like Microsoft office 365 will disable TLS 1.0 And 1.1 on Oct. 15 2020.
Its all about the vulnerabilities in TLS 1.0/1.1 protocols, which includes Heartbleed, POODLE, BEAST, CRIME. Those vulnerabilities allows attackers to intercept the data (like credit card data, intellectual property, credentials) between websites and their users.
The backend business application might take a while to migrate from TLS 1.0/1.1 to TLS 1.2, AppScaler offers TLS 1.0/1.1 and TLS 1.2 interoperability, that means you can still use TLS 1.0/1.1 in business application and AppScaler will automatically convert it to TLS 1.2 to the clients.