Mainly Maps.me is designed for offline use. You get tons of information that Google Map once offline would completely lose.
Also you can bookmark a freeway exit, a metro station - these Google could not do even online. On top of that the place of interest you bookmarked, a hotel would have a bed symbol, a restaurant would have knife and fork, a view point has a binocular, and a museum has a building... Much easier to identify than Google's limited choices of flag / star / whathave you.
Although I lately have an issue of the updates on iPad - the automatic update of downloaded maps somehow got stuck in the middle of update - it would not continue. Moreover it would not download a single map, but if a country has multiple maps, and you choose Download All, it will still download the maps one by one - though you may only need one or two maps out of that country... So you painstakingly delete those you dont want / need...
I have searched online up and down on how to fix it - sadly the only way is to uninstall the app and reinstall it. I do not want to do that now since I have all the spots in Egypt bookmarked, and do not want to redo the whole thing... Plus, I dont know if the unstall / reinstall would solve the issue on iPad... and I definitely do not want to lose the Maps.me for now! It has so much more information than Google Offline on the Egyptian sites, that is very indespensible for now.
Because of the issue on iPad I then downloaded the maps on an Android phone. It works fine. However the screen of a Smartphone is way too small for my eyes...