I would caution against thinking this brings us close to FDVR; there is a fundamental difference between encoding and decoding neural patterns.

Progress like this is in decoding, meaning we take the neural patterns and try and determine what the person was trying to envision. This is analogous to neuralink monkeys playing pong with their minds or people controlling robotic limbs with their thoughts. We are making lots of progress in this area, and we can afford to be imprecise. For example, with a robotic limb, it's ok if your elbow bends 50 degrees instead of 49 degrees for the vast majority of tasks. Even fine motor tasks like writing have a point at which further precision is no longer useful. We also have the benefit of being able to measure the end result easily; we can measure the movement of limbs or the accuracy of cursor movement controlled by the mind.

Encoding would involve figuring out what signals we can put in in order to recreate a specific conscious experience; it is the opposite process of the above. Full dive VR would require us to master the ability to send a signal that gets interpreted by our brain in a specific way. For example, if you're on the beach on a windy day, you'd need to find a way to send a signal so precise that your brain truly interprets it as its own vision, which is incredibly complex. You'd need to find a way to simulate the very complex sensation of wind blowing across your arms, moving your clothes in certain ways, specific hair cells. You have likely never felt the same gust of wind twice, because of how rich our conscious experiences are. In contrast to decoding, encoding has orders of magnitude smaller room for error; if the sensation on your skin is even slightly off, you'll realize it's fake and weird. We also cannot measure the end result of encoding easily at all, since the end result is a conscious experience; imagine trying to describe in words to a researcher that it feels as though your proprioceptive sense of where all your limbs are in space relative to each other feels kind of off. The only way to actually empirically iterate would be to first master decoding, build up a massive database of decoded human experiences, and then simulate trillions of fake walks on the beach into a human brain hoping to get neural signals that, when decoded, are close to perfectly in line with the empirically derived decoded data from real human experiences. This is of course impossible to test on real humans and would likely require server farms lined with millions human brains in jars which, by definition, would have to be sentient and conscious in order to have it be relevant to our own conscious experience.

tl;dr it's good that we're getting better at decoding neural data but it is an entirely different problem from the encoding that FDVR requires. In my opinion we do not have a viable pathway to FDVR due to our inability empirically test neural encoding at the scale and precision needed to make FDVR worth doing.

Yeah, it’s been experimentally proven a few times. The example I remember is that even for speakers of different languages, the word for ‘apple’ in their language lights up the same part of the brain.

It makes sense to be honest. If our brains weren’t almost entirely determined by our genetics, there’s no way we’d all be as smart as we are.