Microservices, when should you break things apart for independent deployments?

we've been building monoliths for a while now, and things are getting a bit unwieldy. we're thinking about breaking things apart into microservices, mainly to get faster, independent deployments. but i'm wondering, what are the real indicators that signal it's time to go down this path? is it team size, code complexity, or something else entirely? keen to hear what experiences others have had when making this switch