Why mechanical innovations were not always introduced into human life?

Scientific inventions improve human life. But new items are not always introduced into a person’s life. This happens for several reasons. For example, due to the fact that in Russia the invention of the steam engine was considered unnecessary, the project did not receive support from the state. And the patent for the invention was given to another scientist. Inventions often turn out to be too expensive and unnecessary. Sometimes they get complicated. Therefore, even professional workers could not work on many machines.