You can indeed live without them. In C++, the trade-off is that you are now responsible for manually writing and maintaining any and all error propagation code, including remembering to check every relevant return value.
Plus you're pretty much screwed on RAII since you cannot return a value from the initializer. So by not using exceptions in C++, you also will often end up requiring a separate init function that can return errors.
I was slightly amazed I had never heard of such a thing, but sure enough, it does exist: It's -Wunused-result on gcc (https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html). You still need to manually add the warn_unused_result attribute to each function though.
There's also the [[nodiscard]] attribute of c++17.
