K8y Memory tagging is going to mitigate a lot of memory based attacks like buffer overflows, but there is no such thing as 'perfect protection' against any kind of exploit ever. If an exploit infects a phone, then memory tagging failed in mitigating the attack.
If I am not mistaken, pegasus was a very specific exploit in Apples messager app related to PDF file handing (I looked it up, apparently it was a link, not sure if the link was to a PDF or if the payload was deployed on the site itself), which they have already patched, and made 'lockdown mode' as well to prevent similar attacks. I dislike when people talk about it like its some kind of 'ultra super hacker' program when its a simple exploit, most likely a buffer overflow in an area of memory thats sensitive.
Stingrays seem to just be man in the middle attacks, acting as false connection points by pretending to be a legitamate cell tower. If you aren't connected to celluar, it can't effect you really.
I have never heard of an exploit related to RFID, I tried looking it up, all I got were people emulating RFID keys using their phone.