Many hotels throw them away if you leave them in the room, even if you didn't use them. They do this for sanitary reasons. So, if you don't use them or take them then not only will the packaging end up in a landfill, but the product too. If you want to be sure, just call the front desk and ask them.
These are great to have on hand to use when you go places that might not have these complimentary toiletry items, like camping. Or save them and put them out for your guests when they stay at your place. They may just feel like they are at a vacation destination when you include little things like that.