I think there's at least a couple of practical applications for the "mark of the beast" being a RFID chip though and some sort of branding/tattoo:
Revelation 13:17 "And that no man might buy or sell, save he that had the mark, or the name of the beast, or the number of his name." The satanists/antichrists are pro technology, even now, the world is. In order to buy/sell effeciently, using electronic payment (today in the form of smartphones and apps) is much more effecient than cash. A smartphone app or an RFID chip is more efficient than using credit card(s).
To facilitate keeping everyone subject to the rulership inline with their rules, one of the punishments to not being inline with the system, would be to turn off the e-commerce "valve" for that specific user. Sorta like how China is using the "social credit score" system today. If you don't stay inline to their system, you lose benefits. So even if their mark is not an electronic chip/RFID transmistter, I don't doubt their commerce system will utilize it (even today some companies/stores are using smartphone apps to pay).
Another aspect to the mark/branding, is displaying their loyalty to their king/beast/antichrist, and his rulership. If everyone can see one's mark when in public/private settings, everyone knows they're on the same team, so to speak. When it becomes illegal to not worship their king/beast/antichrist, not having the beast's mark will enable not just law enforcement, but neighbors, bosses, etc. to identify you to the authorities. The result of this will be imprisonment until you take the mark (or torture), or death for those who resist.
The "mark" could be a two-fold purpose: commerce and inclusion/loyalty/worship to the beast/antichrist and his system/rule.
And the topping on all of this is, it's a sorta "in your face" to God, having His creation oppose Him, publicly.