In Bedrock Edition, powder snow exists as a stackable block. However, in Java Edition, it can only exist in bucket form. There is no other obtainable item form of the block, not even minecraft:powder_snow.

Expected would be that there exists an item form of the powder snow block which can be obtained in Creative (and possibly through Silk Touch), alongside its bucket form for Survival (similarly to how there exist Creative-exclusive fish spawn eggs and Survival-oriented fish buckets).