The comparison video is kind of pointless since they're both at very slow times. If you see a Tokyo gate at rush hour with people packed wall-to-wall but moving quickly, that's what the latency was optimized for. And as others have mentioned, it's two things, speed and distance. FeliCa triggers both faster and farther away. And it never errors; you just made up that assumption. Also in Japan no one walks up to the gate and then fiddles with their wallet. Everyone knows proper transit etiquette from when they're very little.
Sometimes people will be low on balance and get rejected. People reroute quickly in normal conditions, but in rush hour that'll be a huge mess and everyone will be pissed at the culprit.
What you are describing is exactly all the problems with gates. Having them open-by-default improves somewhat. Having 100ms less reading time improves nothing. You are still limited by the speed of everyone else (cultural aspects are irrelevant as they are not improved by reader tech). If you want to improve entry throughput, have _no gate at all_ so that people do not have to bottleneck there. If you really have to put a validator, put it elsewhere.
And where would you put it? Anywhere you can think of would just be another (usually narrower) bottleneck.
In most stations, every available inch of width is used for these ‘gates’, and people move at a walking pace through them except for when people screw up. It’s a remarkably effective system.
Sometimes people will be low on balance and get rejected. People reroute quickly in normal conditions, but in rush hour that'll be a huge mess and everyone will be pissed at the culprit.