Some call it cruel; others, archaic but branding is a necessary function if you own cattle. Yes, we can put ear tags in but they are not permanent. Ear tags can be cut out, fall out, or be altered, etc. Only branding is a permanent nearly no-fail way to prove ownership. Even in 2007 when there was cases of BSE in the US, they traced the animals back to their home places through brand records within 48 hours.
If the animals had tags would it have been quicker than 48 hours-- Maybe? Producers put in ear tags, feed lots take out ear tags, slaughter houses remove them. So, would the information have been transfered? Brand inspections are currently required by law in most states, thus the paper work tracks brands. Leaving a physical paper trail; not an electronic one.
I have lost a lot more information when my computer went bust than I ever have hard copies of data needed. Just sayin.