Characters being brought back after dying is common practice in Marvel Comics and, thus, the films. However, in previous MCU arcs, it would occur on a case-by-case basis think The Avengers re-encountering Thanos via time travel or Phil Coulson being MacGyvered back together by doctors at S.H.I.E.L.D. Now, in the Multiverse Saga, characters can seemingly return at any point by just having them exist outside Earth-616/The Sacred Timeline. This reduces the stakes considerably, not to mention the weightiness of moments like Coulson or Iron Man sacrificing themselves. Now, no character has to permanently die.