Note that even if you share DRAM with the graphic chip, you may take an extra step anyway to rearrange the texture in a tiled format since it's more efficient for sampling.
If you really care about load time you can decode the image directly in a tiled layout in software but that's more annoying.
Yup, in games we used to call this "asset cooking" where you target the platform specific texture compression in addition to tiling that you get as a part of that format.
You get a nice 3-6x memory savings plus put less pressure on the texture samplers as memory bandwidth drops as well.
If you really care about load time you can decode the image directly in a tiled layout in software but that's more annoying.