Josh_Richie
Why would different anime's logic apply here ? You can take different anime's power system or whatever as reference but can't just take them as facts. Eight gates are kinda of filter that stops your physical energy to just flow away. It's more like the more you use the gates the more the life span of your body goes down. They are not blockage to clear to attain long life span. This is Naruto anime logic. The training Guy does is to make his body stronger to handle the after effects of using the gates which is basically abusing his body to squiz out the physical energy get temporary boost. He can't just keep the gate open indefinitely even the first one, he'll just pass out eventually.