I my experience you absolutely must have type checking for anything that prints, because eventually some never previously triggered log/assertion statement is hit, attempts to print, and has an incorrect format string.
I would not use iostreams, but neither would I use printf.
At the very least if you can't use std::format, wrap your printf in a macro that parses the format string using a constexpr function, and verifies it matches the arguments.
_Any_ code that was never previously exercised could be wrong. printf() calls are typically typechecked. If you write wrappers you can also have the compiler type check them, at least with GCC. printf() code is quite low risk. That's not to say I've never passed the wrong arguments. It has happened, but a very low number of times. There is much more risky code.
So such a strong "at the very least" is misapplied. All this template crap, I've done it before. All but the thinnest template abstraction layers typically end up in the garbage can after trying to use them for anything serious.
I would not use iostreams, but neither would I use printf.
At the very least if you can't use std::format, wrap your printf in a macro that parses the format string using a constexpr function, and verifies it matches the arguments.