I have not microchipped my cats. I originally did so with other cats and dogs, but I have heard too many negatives, from microchips migrating to causing tumors. I also have great reservations about such organizations with no security restrictions having that much information about me. In the interest of protecting your pets you will tell these people things you wouldn't tell half your relatives or your bankers. Ergo, it's on my head if they get lost and can't be returned due to lack of chip, but I'm still going to rely on the older methods and my own personal vigilance to keep them safe.
Live simply. Love generously. Care deeply. Speak kindly.
And never regret anything that made you smile.