A few privacy and security features Apple should include in future iOS releases
DNS over HTTPS/TLS option added to WIFI and Cellular DNS settings. (Which will require them to allow setting DNS settings for cellular)
TLS 1.3 support in Safari, with support for Encrypted SNI.
An on/off switch for Internet access for Apps on WIFI, not just cellular.
I’m aware some of this can be done by setting a VPN profile. But it should really be available in settings.