When the food is almost ready, the amount of salt will be much less than when the food is just ready, because salt can't enter the inside of the food, but can only adhere to the surface of the food, so that the food can keep its original taste well. We can eat salty taste, but we won't consume too much salt, which is good for our health. Because the human body needs a certain amount of salt, but too much intake is not good for the body.
Furthermore, especially when frying vegetables, if you put salt first, it will produce a lot of water, and salt will force all the water out of the vegetables. I don't know if you feel this way. On the contrary, if you wait until the vegetables are almost ready before putting salt, the water output of the vegetables will be very small, so it is more conducive to human health to keep the vegetables fresh as much as possible. Therefore, the correct time to put salt in cooking is when the dishes are almost cooked.
It's not that some dishes are not suitable for this. For example, some meat dishes, such as fried fish, have a word here called "salted fish light meat". I don't know if there is such a name in your hometown, mainly because it needs to be salty when cooking fish to make it taste better. You said that if you only sprinkle a little salt on the surface of the fish when cooking, the fish will have no taste at all, even if you put other ingredients in place, it will not taste good. So, when is the best time to put salt in cooking? In fact, it is still necessary to ponder slowly during the cooking process.