This question is based on my recent observation of preferences of certain email service providers and banks to use AES related symmetric ciphers over the more fast ChaCha20 Poly1305 . For example Google's Gmail browser version uses AES 128 GCM but Google's Search uses ChaCha20 Poly1305 ?
Is AES 128/256 GCM in any way more secure than ChaCha20 Poly1305 ?
Despite the fact that ChaCha20-Poly1305 uses processor friendly instructions for mobile devices, and easy to implement in software, why banks or financial institutions are reluctant to adopt it ?
Is it because of specific AES instructions on processors (as far as servers / PC/ laptops are concerned) or because they are sticking to old convention ?