Brains transmit/change state (a.k.a. think) using electricity. It’s basically a flesh computer. You can’t read thoughts without being able to measure the brain’s electrical/chemical activity. If you had any theoretically possible mind-reading (and by extension mind-controlling) technology, it would still need to physically connect to your neurons or something…
That being said, I don’t imagine it’d be too hard for sci-fi future folk to stick a chip in every newborn’s brain from the get-go. But that’s a future too far from now, we’ll all be dead by then probably.