Steps to reproduce:

1. Join a new Creative world.
2. Get any sword from the menu and hold it.
3. Run the following command multiple times:

/item modify entity @s weapon {"function":"minecraft:enchant_with_levels","levels":30,"options":"#minecraft:on_random_loot"}

In this example, a Sword enchanted with Sharpness, Smite and Bane of Arthropods was obtained, as shown on the image below. This is inconsistent with the 'enchant_randomly' function, which can be specified to only enchant the item with compatible enchantments.