This game is designed to be a game of details, explanations, and options. A GM confounded by how a bead of force works need only look to something that creates a similar effect, like resilient sphere, for an explanation of a comparable function. One purposeful gap in the rules exists for artifacts, however. This wiggle room allows a necessary flexibility for exciting items without existing analogs, concepts that buck established guidelines, or ideas that simply prove too elaborate to quantify. There's a place where people besides villains and heroes might find the power of artifacts to hand-wave certain game elements useful, though. The place is at the game table, and the people are GMs.
There's a certain suspension of disbelief that even the most intricately plotted and deliberately planned RPG session requires. Sometimes a player doesn't show up and so her character just seems to vanish. Sometimes new rules present innovations too tempting for established characters to ignore. Sometimes players and GMs just don't want to concern themselves with the details of encumbrance, tracking rations, using alignment, speaking in character, or countless other conventions. Artifacts might serve as a way for a GM to grant PCs an in-game explanation for out-of-game concerns.