The Lee hand press is more versatile, since it takes regular reloading dies in the standard 7/8" size, while the Classic Lee Loader just does one single calibre. Dies are generally cheaper than buying a Classic Loader, particularly used, and you can use dies from any manufacturer, not just Lee.
They're equally safe, and turn out equally good reloads, the Lee Loader is just a bit more labor intensive, in that you have to hammer the empty case into the resizing die with a soft-faced hammer or wooden mallet, versus using leverage with the hand press, or a bench-mounted reloading press.
I don't know why Lee is phasing them out, but I suspect the profit margins are higher on regular dies and presses. Nobody else in the business makes anything comparable to the Classic Lee Loader, though, for the few people who just load one or two calibres, and only fire a handful of rounds per year. These seem to be mostly regular hunters, who make one box of shells last through several hunting seasons.