Honestly? That would be fine in a different RPG. But that's super setting specific sounding, and D&D isn't really a great fit for that as it stands. As a class or ability specific to a setting where that was the default premise, I could see it, but I don't really see WotC publishing that book. They seem too much to want everything to be for everything.Or maybe there's mundane techniques in-universe that detect magic without spells or magic items.
Turns out magic has a special vibration that someone trained to listen for it can 'feel out'. Or a scent like ozone that varies based on type and magnitude.
Anything besides magic is a special thing out of context for the world and not actually a part of the fantasy world.
Interacting with magic as it interacts with the world, I can see a mundane explanation for. Using magical tools to detect and disrupt magical effects, I can see a mundane explanation for. Detecting, not merely the invisible, but the outright insubstantial and abstract and then interacting with it in unintended ways, all without any explanation for it other than their own senses and abilities? I'd need worldbuilding to support that, and the existing worlds of D&D don't have it. As I said in an earlier post, it pushes the line of credulity beyond the breaking point. At least with the current fiction.