For example, the amount of steel used in steel structure is a big problem, so the optimization here is mainly a problem of structural calculation. If you choose a different structural layout, the stress will definitely be different, and the final steel consumption will be different (sometimes even a small change can make a big difference). Of course, there are only a few artificial choices, which are not necessarily what we call the best point. But at present, the optimization problems are basically solved by gradual mathematical methods. Of course, for simple problems, practical engineering can be transformed into mathematical problems for computer processing. But buildings are generally very complicated, which is also the difficulty of building optimization.
The advantages are more economical, more reasonable, more environmentally friendly and so on (that is, to make the above five effects more in line with people's requirements).
But nowadays, ordinary buildings rarely deal with optimization problems unless the situation is very special, because structural designers are anxious for time and efficiency, and the design is basically too big. Let designers optimize, that is, let them brush the edges better, which is not what ordinary designers can do.