The Time Runs Out arc was one of the best arcs in Marvel history, everything after it feels just pointless.
The Beyonders were so powerfull that they easily destroyed the Celestials, Eternity, Inifnity, Galactus and even the Living Tribunal, they destroyed Decillions of Universes and nearly wiped out the entire Marvel Multiverse. It was/would have been fitting for a Grand Finale. (How they were defeated is a different matter, but oh well)
What comes after them? The First Firmament - stronger then even the Beyonders and wants to destroy the Multiverse......
Thanos with the Astral Regulator can suddenly absorb the Living Tribunal AND even the One Above All...
The Griever at the End of All Things effortlessly kills the Molecule Man who absorbed the collective powers of all the Beyonders....
Its just to much. You cant just spit out one foe after another that can crush the Living Tribunal (the manifestation of the entire Multiverse) without effort. You just cant threaten the destruction of the entire Multiverse again and again after it was averted allready. In terms of power and destructivness Marvel has reached the Top. Raising the stakes by threatening to destroy more than the Multiverse/Everything? Comical. Raising the stakes by introducing an enemy stronger than the Living Tribunal/The One Above All? Ridiculous.
What can Marvel Comic offer now that they reached the absolute top?