The steady state theory has a lot of drawbacks. In particular, it has trouble to explain the observation of the cosmic microwave background (among others). For that reason, it as declined for about 50-60 years and is barely considered today. Here is a nice source with extra pieces of information, if you are interested.
In fact, this whole story is actually exactly how science works. New ideas appear, their predictions are compared with data and then either the theory survives, is refined or it dies out.
Cheers!
Thank you for the link :)
You are welcome!