I honestly don’t think there is a replacement for Google Maps, I use Organic Maps from time to time but it is more difficult to use, rarely can I just input the name of a business and it finds it.
I suppose using it like a directory for restaurants and attractions could be done through the browser without an account but it is hard to deny Google Maps is a fantastic resource and hard to replace.
This looks interesting, it could be good to get away from Google. I never think about other proprietary system I always think first about moving to Open Source solutions.