There are maybe 2-3 instances where you could make the arguments for limited revives; examples being contest raids/dungeons, and mayyyyybe conquest. Outside of that, there is zero reason for them to exists in your run of the mill matchmade portal activities, especially the arena ops. Most players that are going in to matchmade activities are going in to just chill, do the shooties and get the looties. Limited revives, especially in the chaos of arena ops where most players are just loading in without thinking about their builds, kills the enjoyment. Limited revives is too punishing of a mechanic. There are enough negative modifiers in grandmaster/ultimate as it stands without limited revives being thrown in.