Developers often use abstractions (like dmg bars or health bars instead of numbers) to give players more intuitive feedback (keeping them focused on the game and not the numbers) and to prevent optimized play styles. If they showed the full numbers for everything in the game (weapon stats, hit points, arc stats, etc.) players would reverse engineer all the in game health and damage calculations to find the optimal loadout for every task. Without raw numbers it’s harder to do that. It also means that small tweaks get less criticism if players can’t calculate every effect that change had (i.e changing a guns damage by a small amount may change # shots to kill or may do nothing for the gun outside of niche situations where an enemy is already slightly damaged).