TriPlanar projection is a nice little feature but it has it's cons.
The way it works is that it projects 3 versions of the same texture (1 per axis) using world coordinates. It is close to a cube projection, the only difference is that it basically ignores size and rotation, it is always using world coordinates. In some versional of TriPlanar projection you have the ability to adjust the blending border and the randomness for the texture angle as well as texture position within projection. So you can shift, rotate and tile texture within those 3 axises.
The down side of TriPlanar is that it doesn't really work well on moving objects
for obvious reasons
and you can't go precise if you need to. So it will work fine for abstract noises (like scratches, smudges, and etc) but once you decide to place a scratch or a fingerprint smudge on a specific spot on your model - you'll struggle
)
In Maya, for instance, we already have something similar - called Texture 3D - it is a version of TriPlanar projection. Can't say I've ever used it
Having TriPlanar projection method is probably a good idea, so that way you can easily add random grime, wear and abstract textures to some objects, especially for those of us who is using software which can't offer a really nice UV editing tools.