Many circuits take "3.3 - 5V" inputs, so a 3.3V driver will usually work... unless literally anything goes wrong. They will usually work as far down as 3V, for

Many circuits take "3.3 - 5V" inputs, so a 3.3V driver will usually work... unless literally anything goes wrong. They will usually work as far down as 3V, for that matter. These are analog systems, and there's a big difference between "works" and "works reliably, for months and years".