If I am working at a coffee shop, or out of town and bought something that needed to print a receipt, or a confirmation, or anything else. I could print it through Google Cloud Print and it would be ready and printed for me when I got home. It was just a nice convenience that worked every time.
Yes there are alternatives... most printers now have an obfusticated email address that you can send to and it will print from. But this is vendor specific and unreliable and required additional steps (had to save to computer, then open an email client, send an email, etc).
But then again, how can I be surprised? We are talking about Google, the company famous for shutting down projects. I wouldn't be surprised if I wake up tomorrow and they shut down google.com search engine. Right now on Hacker News (just a few spots above this post) is a another site [1], which hosts a countdown for when customers expect to shut down the Google Stadia product... a product that only launched a few days ago.