> Do you think that the vast majority of software devs moved to typing for no reason?

It is quite clear that this industry is mostly driven by hype and fades, not by empirical studies.

Empirical evidence in favor of a claim that static typing and complex type systems reduce bugs or improve productivity is highly inconclusive at best

It's a bad reason. A lot of best practices are temporary blindnesses, comparable, in some sense, with supposed love to BASIC before or despite Dijkstra. So, yes, it's possible there is no good reason. Though I don't think it's the case here.

We don't actually have empirical evidence on the topic, surprisingly.

It's just people's hunches.