2 MP, f/2.4, depth
No, Vivo Y78T does not offer any kind of IP rating and it is not waterproofed.
Vivo announced 1 major Android updates. So last update will be Android 14.
Vivo announced 2 years of security updates for Vivo Y78T, so it will receive patches approximately until 2025.
No, Vivo Y78T doesn't have Wi-Fi 6 version or newer.