It seems that aside from the matter of the locusts consuming what was left in the fields, the locusts do not cause any special death more than the other plagues, because naturally, snakes do not come with the locusts, and they do not blind the eyes. From my personal experience, they are not even bothersome in their presence, as I observed when I arrived to study at the Staten Island Yeshiva as a young man, and it was during a locust plague that occurs there once every twenty-two years, and they instructed us to ignore them as if they were not there: 'Sit on them, step on them, they do not bite and do nothing.'

It can be said that therefore the common Egyptian people were not afraid of the news of the locust plague, because instead of the loss of the locusts eating the crops in the fields, they would have plenty of food from the locusts that they would salt and fill the barrels.

And why Pharaoh eventually asked to remove 'this death' from him is because the Holy One, blessed be He, made it in a miraculous way, that the quiet locusts would now bring upon them a death that is not in the natural order (see a similar idea in Rashi's commentary on Deuteronomy 32:24). This is to show the Egyptians that Hashem is the 'master of the house' of the world, and at His will, 'even a broom can shoot,' as people say.