I found a few small Protestant monastic groups with a little searching, but they seem to be small and far between. I'm aware of Luther's reforms leading in part to the dissolution of many existing monasteries, but I'm wondering why in the intervening centuries a Protestant monastic tradition hasn't grown or taken root?
It's very difficult to argue for "why something didn't happen", because that's not really how history and causality work. Indeed, the question as you put it sort of hinges on supposing that monasticism of some sort should have taken root.
We might approach your question from two angles though. Firstly, the Reformation was decidedly anti-monastic. Reformers considered the ongoing belief in the superiority of chastity over and against the 'ordinary' life of marriage and family to be Biblically unfounded. They thus rejected it pretty categorically. There was a theological reaction against monasticism which dominated Reformers.
The second approach would be to consider how monasticism developed in the first place. In the context of late antiquity, the decline of martyrdom as a real 'option' for the most dedicated Christians; the very high regard placed on virginity, and the significant role of asceticism in late antique Christianity, all led to the development of monasticism as a key feature of European Christianity towards the end of Late Antiquity/Beginning of the Middle Ages. Those features are largely absent or subdued in the birth of Protestantism and so (those particular) catalysts for some kind of neo-monasticism are not present.
Many (not all) strands of Protestant theology have historically rejected monasticism as corrupting because they perceive that it isolates monks and nuns from their communities and it elevates them falsely to a higher status than the other community members. The idea being that everyone should have a relationship with the divine, not just clergy or monks etc.
Of course there are Protestant monks and nuns and plenty of non-Protestant orders in the present day do loads of work in their communities, but traditions die hard and Protestantism has a very strong tradition of just not doing the monk thing.