Forget Siri, just update the damn Spotlight which makes iOS pain in the a$$ to use. What can be done with 1 tap (or even just by typing) needs multiple actions in iOS. Example directions:
iOS:
1) pull down to open spotlight
2) type address
3) realized you can't open it in Google Maps
4) close spotlight
5) swipe left and right to find Google Maps app
6) give up, open spotlight again
7) search for google maps app
8) open the app and type the address again
9) tap navigate
Android:
1) open Google search
2) type address
3) tap on first result
4) tap navigate
Sometimes I try to search web and then open Google Maps from Siri, but half of the time it is unable to pass the address to the app so I need to type it again.
Or you could just open the app, type the address, and tap navigate. Probably easier than the 9 steps you describe.