Grenades vs. passive skill tree

Good morning,
GPT claims (yes, I'm a beginner, so I ask him about everything lol) that grenades have their own mechanics, and crossbow/damage perks other than explosion/grenade do not actually increase the damage of the explosion, even though they visually increase the DPS stats. Can anyone tell me what is true and what is not? In builds, people give perks to % from two-handed weapons, but no one gives them to crossbows (build for grenades). Best regards!

Everything works that should.

Attack, AoE, 2-hand, grenade, crossbow, projectile.