> you should be interpreting them at time of reading the log

This reminds me of a fun interaction in browser devtools: you can log a complex struct to the console. The browser does not copy the entire nested structure when you do so immediately, meaning that if someone mutates that struct after it was logged, the value you see depends on when you expanded the nested struct.

The thing is, the logging calls already accept variable arguments that do pretty much what people use f-string in logging calls for already, except better. People see f-string, they like f-string, and they end up in logs, that's really all there is to it.