Okay seriously though, the Phantom Ruby is severely underutilized. Based on what happens in Forces alone, 1. it can create enemies and cube-y attacks, 2. it created copies of people who were exactly like the originals in terms of power and personality, just loyal to the Eggman Empire, 3. it connected to Classic Sonic's dimension, and its destruction transported him back, and 4. it created Null Space. And then in Episode Shadow, Infinite 5. creates an entire "level" to trap Shadow and Omega in, and 6. sort of ... "hypnotizes" them into thinking that the scenario they're in is real? Or something?
Combine that with Sonic Mania's time-space warping, power-boosting a group of Egg-Robos, and making them sapient and rebellious, and suddenly you've got an artifact with massive potential which can do way more than even the Chaos Emeralds have ever demonstrated. Like, forget a game with the awkward length Sonic Forces ended up being, you could get a whole season of a TV show out of just that one item!
Dropping a sun on the Resistance during the last part of the game, and Infinite growing into Infinitezilla during Operation Big Wave, should be particularly tame examples of what happens with the Phantom Ruby, not outliers.