A look into a future where things assume you have a smartphone
My local bike club has increasingly been going paperless for bike ride routes. I've been a paper holdout, but recently I pushed myself into deciding to finally get a bike GPS unit for ride navigation. Naturally this led to a frenzy of Internet research on the whole area, the summary of which is that there are only two serious competitors in this area right now (which is much less than I was expecting).
At this point, Garmin has probably been making the Garmin Edge series of GPS bike computers for a decade or more, and my impression is that they haven't fundamentally changed how they work over that time. As you'd expect for something that originated so long ago, they're pretty much self-contained boxes that believe in doing most everything themselves (although modern models can use your smartphone as a peripheral). On the one hand, this makes them pleasantly easy to deal with even from things like Linux machines, because they require so little from your computer (an Edge unit presents itself as a USB disk, and you do things like transfer ride routes to it by putting files in a magic directory). On the other hand, a Garmin Edge is a slow, pokey device with a relatively small screen by modern standards and because the Edge is determined to do everything itself, your experience is very dependent on how well it implements things like turn by turn directions. Sometimes this does not go well, and in general the experience of working with an Edge is not exactly fluid and fast.
The Wahoo Elemnt is Garmin's only serious competition right now, and it has taken a very different approach. Rather than try to be self-contained, it fundamentally assumes that you have a smartphone and so your Elemnt offloads a bunch of preparation work on to it and the outside world. Configuring the Elemnt for things like what data fields get displayed? That's done through the smartphone app, using the smartphone's much bigger and more responsive display. And in what I care about, route planning and preparing turn by turn directions is outsourced to various existing websites that specialize in it (and that do a good job, giving me a lot of control and the ability to fiddle with things in advance). The Elemnt can still be a standalone device when you're riding, but its clear philosophy is that it is one component in a larger environment and it doesn't have to try to do everything itself.
(Like modern Garmin Edges, the Elemnt can use your smartphone as a peripheral in various ways during rides.)
The Garmin philosophy of being self contained made a great deal of sense ten years ago, and probably was pretty much necessary at the time. Ten years ago Google Maps had barely been launched, high speed Internet was a lot less high speed, computers were slower (and screens smaller) and probably less prevalent among cyclists, smartphones were barely there, and so on. Really, there was not much of a greater environment to be part of. But I think the Wahoo philosophy clearly makes a lot of sense in today's world (even if it's inconvenient for me, since I don't have a smartphone yet). A GPS bike computer that can run for ten hours or more under the hot sun with the screen on and GPS going will never be able to compete in screen resolution, processing power, or responsiveness with a decent smartphone, so why even try? Build something that's relentlessly specialized in what it can do well, and let smartphones handle what they're good at.
I didn't expect to get a look into the future when I started researching GPS bike computers, but I think I have. I can't see any reason for the Wahoo Elemnt approach not to become more and more common over time; more devices will just assume that you can interact with them through your smartphone, and in fact that you'll want to because it gives you a better experience.
(Yes, there are some things you give up when devices stop being self-contained. It is potentially useful that many Garmin Edge models can work out routes all on their own, for example if the skies open up and I want to bail out of a bike ride in order to get home as fast as possible. You can theoretically do this in the field with an Elemnt and your smartphone, but it's probably not going to be as easy.)
PS: This may be less a look into the future and more a look into an increasingly prevalent present. I don't look into modern electronic stuff very often, so I wouldn't be surprised if there's already a lot of things that require you to have a smartphone and I just haven't noticed.
PPS: The Magellan Cyclo series appears to be strictly inferior to the Garmin Edge if you primarily care about navigation. At least as far as turn directions go, it definitely takes the self-contained 'I know better than you' approach (and it doesn't necessarily).
(I have acquired some opinions here, as you can tell.)