The question is no longer, “What phone should I get?”

That was an important question immediately after the arrival of the iPhone and its competitors. But now it's time to admit that today's smartphones (and tablets) are nearly identical. Apple and Google (maker of Android phone software) have copied each other's ideas so completely that the resultant phones are incredibly close in looks, price, speed and features.

These days the Apples, Googles and Microsofts of the world are competing on a different battlefield: they're racing to build the best, most enticing ecosystem. Each is creating a huge archipelago of interconnected products and services. It's about velvet handcuffs: making it easy for you to embrace its offerings and as hard as possible to switch to a rival's.

A typical ecosystem includes hardware (phone, tablet, laptop, smartwatch, TV box); online stores (music, movies, TV, e-books); synchronization of your data across gadgets (calendar, bookmarks, notes, photographs); cloud storage (a free online “hard drive” for files); and payment systems (wave your watch or phone instead of swiping a credit card).

For consumers, the choice is now what suite of products they like best.

If you're one of these companies, though, you've got a difficult decision to make: Should you open up your services to people who use your competitors' products? Say, let an iPhone user load an Outlook calendar or let a Microsoft Band smartwatch wearer sync data to an Android tablet.

On one hand, making your software available to those outside your ecosystem could introduce the rest of the world to the superiority of your products—and possibly bring in new consumers.

On the other hand, you would lose the exclusivity of those services as a lure. Why would anyone switch if she or he can already get the best of a rival's offerings?

So what approach are the giants taking? It's a mixed bag.

Apple is the most closed. In general, it writes apps only for iPhones and iPads. You can't make a FaceTime call to an Android or Windows Phone, for example, or run the Apple Maps app on those devices (not that you'd want to). And you can't use the Apple Watch with anything but an iPhone. You can, however, use Apple's iCloud (online file storing and sync services) on a Windows device—but not on one using Google's Android.

Google goes to great lengths to make its wares available to other platforms. If you have an iPhone, you can use Google's apps (Gmail, Chrome, Google Maps), services (Docs, Sheets, Slides) and even digital store (Books, Music, Newsstand). The services and store are also available to Mac, Windows and Linux users. You can even link an Android Wear smartwatch with an iPhone.

Then there's Microsoft. Microsoft Office is available for just about anything with a screen, as are many of its mobile apps.

Why such inconsistency?

It helps to understand the individual corporate motives. Although these three companies offer so many similar (okay, almost identical) gadgets and services, each is actually running on an entirely different business model. Apple is primarily in the business of selling hardware; Microsoft, software; Google, ads. Each has different considerations in calculating what to open up.

And Apple and Google continue to branch out; both now offer, if you can believe it, software for your car dashboard and home-automation system designed to work with their respective smartphones. Surely Microsoft won't be far behind. Samsung boasts its own cluster of competitive products and linked services. Even Amazon—once a bookstore, for goodness's sake—now makes phones, tablets and TV boxes.

You, the consumer, should be delighted by this direction. Perhaps dismayed by all the duplication of effort but happy there's competition, which always begets innovation (and often lower prices). And you should be pleased that overall the trend seems to be for these companies to make more of their services accessible, no matter which phone or computer you own.

Eventually the ecosystems may well become nearly identical, too. Maybe at that point, the question will once again become, “What phone should I get?”