Aren't spell ingredients made meaningless by the focus/holy symbol/whatever that casting classes get automatically? The only time I could see them being needed is if the character loses those items, an NPC without a focus, or a newly multiclassed character.
Personally I would prefer a lower material cost for spells but no focus/holy symbol/whatever. Something that functions more like arrows/crossbow bolts, so different types of magic consume different types of less than common items that can be bought at magic shops or looted of magic using opponents. At least that way you can run out, and the cost can scale in a way that is more intuitive for more powerful spells.
I think some ridiculously poweful spells should still have a high barrier in terms of materials. That way a character's individual quest could be to gather these rare materials that could elevate them to godhood, change something from their past etc.
My party literally has a halfling corpse in their bag of holding. That corpse has served its narrative and clue-based purposes. It's still there. I've called attention to it. They are well aware. It's still in there.
I have replaced my wife's purse with a bag of holding, let's see how she reacts when she's digging around for her lipstick and touches a dead hobgoblin's face.