My Layla and Jake are both microchipped. I had Layla done with Avid at my vets. Her's seems to have moved a bit when I had it checked. Jake was chipped at the shelter with Home Again and my vets were able to read it.
I had Layla chipped after Kay's Kiara went missing. What 'if' your dog was missing, three months later, you see her sitting on someones porch? How do you prove she's yours? Pictures, maybe, maybe not.
My dogs always wear collars with tags on also.