Why are steam engines not being used today?

Steam engines are largely obsolete today due to advancements in technology that offer more efficient and powerful alternatives, such as internal combustion engines and electric motors. These modern systems provide greater energy efficiency, lower emissions, and reduced maintenance costs. Additionally, the infrastructure and fuel supply for steam engines are less practical compared to contemporary technologies. While steam engines are still used in some niche applications, they are no longer suitable for the demands of today's transportation and industrial needs.