RAI isn't really meant to be an inflation hedge but in theory people can create a price index and then index RAI bonds against it which would then allow you to maintain your purchasing power.

TIPS and I bonds are in my opinion the way the economy should work everywhere. Yes it means nominal yields can be negative but the entire point of the concept is that the unit of account should be stable and not inflating. Even if rates are excessively negative, it is still more predictable than inflation and you know exactly how much you are losing and prices will stay the same so your salary doesn't shrink over time.