No instant cast ranged ability with should be doing more than 25% of someone’s HP if both players are the same level and have relatively equal gear.
The prime offenders right now are Startsurge and Shadow Word: Death, but this should apply to all instants now and in the future. The only reasonable exceptions are instants that require significant investment from a cooldown or resources (Presence of Mind or Arcane Surge for example) or require a proc related to getting other casts off to use (I.E Hot Steak, Brain Freeze, Nightfall ect).
Hard hitting instant casts make sense on melee characters, because you can kite them or CC them to prevent said damage, or at least slow it down.
That’s the game. Melee hit hard so don’t let them touch you, ranged can also hit hard but have wind up time for said abilities and have to dance around keeping melee off them and “stops” from other ranged classes (counterspell, spell lock, earth shock, feign death, avoiding CC ect)
Please tune the game blizzard. SoD has been some of the most fun many of us have had with WoW, and its even better that it’s in a classic environment but without some much needed tuning PvP is going to stay a cancerous one shot FOTM fest and it’s a shame because PvP in classic is a major part of its charm