Think about this.
If you're amazing at spacing, how unsafe are you really?
If your enemy doesn't know what you're about to do, how much time are you being 'given' due to the extra few frames they need to analyse/react?
ff aerial to jab is a pretty simple example.
on shield it isn't safe
but we ff an aerial which is safe into a jab which if they continue to shield will be unsafe, but get away with it.
Stuff like ftilt, back air (ff, ac, etc) have frame 'unsafeness' but have other properties (range, good start up primarily) that over come such disadvantages. They aren't overly telegraphed either, me facing backwards towards someone with Marth is a position opponents have to respect in like 90% of match ups because there's more than just 'bair'.