. I actually thought about responding the same way.
But to expand on this for the sake of fun, the microchip by itself is useless. You’d also need a transmitter to send data out of your body. That would now also require a power source (battery or some advanced way to tap into the electrical impulses of the human body). That transmitter would need to be powerful enough to reach a receiver (cell tower) and more powerful means bigger. If the goal was to track your movements, you also need a receiver to receive the gps signals from the satellites and a processor (unless that is what that first microchip will do), to convert those signals into a location to be sent back. Then you need data storage, transistors and resistors, wiring, encasing, etc. Now, we’re not just putting a simple microchip in the body but we need to build a whole minicomputer that is getting even bigger and bigger. As you point out, even the microchip is already too big for the syringe let alone this much bigger and complex minicomputer.
Why haven’t anyone found one of these minicomputers on an x-ray? Where are all those reports? More importantly, why would any government spend any amount of money on these minicomputers when virtually everybody (including these conspiracy theorist anti-vaxxers) already have spent their own money and can be tracked today? It’s called a smartphone (which is a computer).