Firebase Software Engineer Michael Hermanto says that the company introduced the URL shortener in 2009, and that since then, the ways in which people share information on the web has changed, while additional URL shorteners have grown in popularity. He notes that Google is refocusing its efforts by replacing it with Firebase Dynamic Links (FDL), which allow users to redirect to specific locations in iOS, Android or web apps.1
Yes, there are alternatives such as Bitly and Ow.ly. FDL, however, does not seem like a direct replacement for Goo.gl.