As per my understanding, we are here talking about whether to have a generalist profile, or bein a multitasker, and to have a specialized one. It all depends on what are your perspectives and career goals.
It’s true that specialists are far more capable in a given topic. Specialists would have put the necessary time and energy into studying a topic to come close to mastering it, this process develops other useful skills. That would bring you Product Knowledge. But that would also mean doing the same redundant work for a long time. Would you be able to do it? If necessary, would you be able to exit your comfort zone after passing all this time doing the same work?
A generalist however can do any kind of work at any point of time. A generalist pursues whatever whims occur, he may branch out further than a specialist. Which makes a generalist more adaptable and this may let you acquire a lot of varied experience and quality output.
As far as I am concerned, when you know a lot of nonspecific stuff about a topic, you are more likely to find your place in the world. If you are so specific that only one or two places will know what you are about and accept you, it makes life extremely hard. And we can often observe this phenomenon into multinationals that proceed to company restructuring. In this case, some people need to move to other roles. But because they are specialized, their profiles may not find their place again.
Wishing that my answer could help you.