This will be only my opinions based on over 40 years of SAK EDC, nothing official and probably wrong and/or biased.
The SAK is not my only EDC knife, it complements a stockman which is a better cutter for my particular way of life, the SAK handles many everyday needs very well, including many non-cutting things.
The steel is made to be very rust resistant and easy to sharpen, it will take a good edge and hold it long enough to satisfy most people, though most people let it go dull because they don´t know much about sharpening, it is tough and to my taste a bit soft, I would like the cutting blades and the files to be harder.
The plastic handles are their weak point, they can come loose, fall off and break too easily, the alox handles are very good, it is easy to replace the plastic handles (epoxy them on) and to make custom handles.
A SAK will last as long as you take care of it, keep it clean, dry and sharp, don´t abuse it, and it will serve you well for many years.
The tools are very well designed and made, fit and finish is incredibly good for the price, especially considering how fast they make them, truely Swiss engineering at its best.
There is room for improvement, better handles, harder steel, more models with locking blades, fancier and more modern gadgets, this will be coming as natural evolution.
SAKs should be allowed in airplanes, schools, everywhere. Everybody
should have a SAK, including kids as soon as they are reasonably mature and responsible (something hard to judge but we as parents can do it).
There have been attempts by other makers to make similar knives, some get close, but not quite.
Probably good alternatives to SAKs will come, multitools based on the Leatherman design are getting close.