When it comes to steaming, electric pressure cooker and steamer work in the same way. Generally, electric pressure cookers can replace electric steamers in all steaming cooking for dishes such as vegetable, fresh pasta, fish, etc.
Electric pressure cooker works better for two reasons.
Faster and Deeper
Under high pressure, steam penetrates the food in very evenly, deeply, and quickly manner. This is why electric pressure cooker is faster than ordinary steamer. Electric pressure cookers are especially good for tough pieces food, such as big potato or yum, fish or meat.
Clean and Green
Electric pressure cooker such as Instant Pot has a fully sealed cooking environment. No steam escapes the cooker. You only need a small amount of water (e.g. a cup of water) to steam vegetable (corns, peas, broccoli, cauliflower, etc.) fresh or frozen. And it takes just a minute or two. This makes electric pressure cooker more energy efficiency leaving your kitchen cooler and free from excessive humidity.