But they work better for iOS users than anything natively available for Android, which is a bit ridiculous considering its 85%+ market share.
There is no video calling solution on Android that you can use out of the box that will reach every other Android user without first having your contact manually install an app and possibly sign up for service. And yes, any SMS app will allow you to reach the same number of people as iMessages, but iMessage offers additional functionality for any contact who happens to be using an iOS device as well. That of course will vary widely but at least here in the US, that probably represents a pretty good portion of your contacts. There is nothing natively comparable on Android, which still blows my mind considering how many more Android user there are.
Yes, there are tons of applications that can do everything iMessages and Facetime can do, and more but the barrier of entry vs. Apple's native solutions is the limiting factor, and why so many iOS users profess that leaving them behind requires too much compromise.
Alright, my apologies in advance for going off on this tangent...it's been beaten to death numerous times but it still is a relavent point concerning iOS users switching to Android so it's at least moderately pertinent to anyone considering switching from iOS to Android and in this case, specifically to the S8.
I mean, you are correct....but as Jamezr mentioned, you have NO control over which devices receive the messages/calls, etc. You have to go and sign out each device manually, and you also have to (in my case) uncheck a million emails that could receive said messages.
As an example, although not exactly normal, my father uses my itunes account to log in on his work phone so that he can use the apps I have purchased. I know there is a family library, but that is just how he does it. Anytime he logs in, or I log in a new iOS device, we have to go and uncheck all the emails, phone numbers, etc from iMessage and facetime....or I start getting his work messages and he gets my messages. So, while it is integrated, it is far from seamless for anyone except the simplest of setups.
As a side note, unless something has changed in the last month, the family library on iOS is VERY poorly implemented, compared to Android. Android's family library is integrated with the play store so that if you look up an app, and someone in your family already paid for it, it says "family library" and allows you to download it. iOS doesn't do this, and if you search for an app, it won't tell you if someone sharing your account bought that app already. You have to go to the "purchased" tab and scroll through ever app you have ever downloaded. Unless this has changed (and it may have), this method is half-baked.
Anyway, contrasting iMessage and Facetime to allo and duo (or hangouts, I just think allo and duo will be native soon), you simply download the app and you are off and running. If the person doesn't have allo installed, you can still message them (and said message, along with your content, will include a link to allo). So while this is not native, it is an equal to lesser complicated solution.
Both work, and both are the results of the respective software's approach; thus neither is perfect.