One of the reasons that there are so many is that they are very specific.  Even if, like the EU Eco-label (the 'flower'), they are applied to many different products, the criteria for each label type will only be relevant to a particular aspect of the product, or a specific manufacturing process.

Some labels are highly specialised: paper labels, for example, that only cover recycled content, or forest management.

Even those that are lifecycle based, such as the EU Eco-label, will vary. The environmental impacts of manufacturing paper are very different for those in printing, and different papers also vary, so a paper label will consider different topics and will also set different levels for use of water or energy, based on what is achievable for that particular industry. So there are different labels for different products; in this particular case, Copying and Graphic Paper, Tissue Paper and, soon to be published, Printed Products.

The diagram shows a very summarised version of the life cycle of a printed product to indicate where the various more common labels apply.