I’ve remarked on a few occasions that an essential decision in Fate is how big aspects are. That is, should aspects be the big, important signifiers of what really matters, or should they be more of a language to express the moment in mechanical terms.
As Fate has evolved, it has gone more down the second path, and there are a lot of benefits to that. It is fairly easy to turn any scene into a handful of aspects, and by extension have the baseline mechanical attributes you need to run the scene. That’s a useful tool.
But it’s important to note that plenty of other system can do it. If I’m doing a Risus or WaRP variant, I can assign d6 pools to any arbitrary thing you can think of (On Fire 3d, Deep Shadows 2d). In Cortex Plus I can do similar things with a die value (on Fire d8, Deep Shadows d6). If the game has reasonably flexible descriptive mechanics, it’s pretty doable.
In this context, the main feature of Fate is that it’s simple. In each of the examples above, a little bit of thought needs to be given to assigning a rating. Is this a 3d6 fire, or a 4d fire? What’s the difference? Sometimes that can be easy to intuit (especially if you know the system very well) but it’s still an extra step. In Fate, it is simple On Fire or it’s not.
Obviously that’s double edged. There are times when you might want granularity, but that is the nature of tradeoffs. The right answer is the one you need right this minute.