For the majority of history God hasn’t worked in obvious miracles. Relatively speaking, the Bible records only very small portions of history, sometimes interspersed by hundreds of unrecorded years, and even in those records God isn’t performing miracles all the time. You’d expect the Bible to record a fair number of miracles, though, because it is often a record of very special occurrences, when God interacts openly and obviously with people for various reasons.
However, all this is not to say that God doesn’t do miracles even now. It’s just that those miracles might not be obviously so.