I am fortunate to have experienced multiple JAL F and C flights between US and TYO over the past few years. I think the cost cutting became more evident last summer.

-F used to get a nice Jean-Paul Hevin chocolate inside a box, one per F passenger. Since my flight last December, they changed to two small chocolates.
-The F lounge used to get 飛龍 sake and now cheaper brands.
-Fewer special midflight food items, and replaced with Vegan dishes. I think it's a good change, just now there are fewer choices for people who aren't vegan.
-Desserts have become a lot more simple, like a piece of cake or mousse. But it could be the season or chef, so not definitive.
-BC Amenity kits like mentioned above. But JAL has never been like EK or SQ giving full size cologne and other products, so not much of a downgrade for me.
-"Cost cutting service"? The CA prioritized Japanese passengers and I had to wait for a long time to get service for midflight snack and breakfast. Just an observation, maybe they have elite status or the crew are also fed up with foreigners/overtourism/tiktok and instagram influencers/miles chasers.