Hyperbolic comparisons like these are very off-putting for me too, but I see them everywhere, presumably "for effect". The effect in this instance is that I stopped reading.
I'd saying having the yearly GDP of Bulgaria as AUM is still pretty impressive. And the point is more to contextualize. It's hard when you get past the millions to understand exactly how much we're talking about.
It's a bit odd though because I doubt the majority of readers will have any direct experience with Bulgaria to put it in context. It's like trying to explain X in terms of Y, when Y is equally unfamiliar.
It is 1/4th of Toyota's or Volkswagen's revenue of one year, so not that much. And last time I checked they did not create a game for recruiting tech talent either.