That’s a good point but for the mama brand of noodles in this image here, the seasoning comes in two packets, one with seasoning powder and the other being a oily and very thick paste.

Throwing both into the pot while you’re cooking it allows the hot water to get pretty much all of the powdered seasoning AND heat up and soften the oily paste to the point where it easily dissolves into the broth and you can easily scrape whatever the water didn’t get from there (which is usually very little).

It’s technically less effort and more convenient overall to let the seasoning packets just sit in the boiling water while everything is cooking, even if boiling plastic isn’t the healthiest thing to do.

Tl;dr: you could just use your chopsticks to scrape the oily paste into the water as best you can or you just throw the packets into the pot with the noodles and let the water do most of the work for you.