Run this shortcut just before leaving some place to go home and it will tell you how long it will take and then send that info in a text to someone you choose, perhaps someone who's already there and would like to know when you'll arrive. The handy thing about this shortcut is that to get your ETA from Google Maps you need to actually start the directions running, when most of the time I already know how to get home, so this saves you from having to go through that whole flow.
When you download the shortcut, the shortcut will ask for your home address and the person in your contacts to send the message to. This information is only stored and your phone and not sent to me or anyone else. Then you just need to run the shortcut when needed and it takes care of the rest.