The TLS protocol is one of the foundations of Internet security. In
recent years it's been under attack: Various vulnerabilities, both in
the protocol itself and in popular implementations, showed how fragile
that foundation is.
On the other hand new features allow to use TLS in a much more secure
way these days than ever before. Features like Certificate Transparency
and HTTP Public Key Pinning allow us to avoid many of the security
pitfals of the Certificate Authority system.