My boys are microchipped. I can see what Joe4d is saying, but chipping has caught on here and it is now law that every horse in transit has a passport with them, and the chip number is in their passport.
It cost me about €30 each to chip. Every TB in the UK & Ireland is chipped, we don't lip tattoo. I find it worthwhile, and many yards require the passport and chip be checked before the horse is allowed off the horsebox.
Maybe it will catch on over there, I don't know, but it seems to be working well enough here and they have now moved into chipping saddles.
Stop for a minute, open your mind, learn. You may not agree with what I say, I may not agree with what you say but we will both learn something new.