Mobile bandwidth hog
Edge does have partial support for the related srcset attribute on the good old img tag, which means developers can target high-resolution screens with larger images, but Edge lacks support for the bandwidth-saving sizes attribute, which seems like a serious oversight for a browser targeting mobile devices.
Though, to be fair, Safari Mobile also lacks this feature and Microsoft's development tracker said Edge's support is "in development".
The only time you're likely to run into problems with Edge are if you're using cutting edge features like the Picture element, but in most cases you'll run into the same problems with Safari, Mobile Safari and (to a lesser degree) Firefox.
In short, while Edge is a giant leap forward for Microsoft when it comes to web standards, it's more a small step when compared with its rivals.
Chrome... is looking considerably less svelte than it did back when it first launched despite the fact it continues to have excellent standards support
Provided that's true, Microsoft may have done the web the biggest favor since Mozilla forked Netscape to create Firefox, namely creating some good old healthy competition for the current darling of browser developers, the WebKit project.
The WebKit rendering engine and Google's fork, Blink, account for all the traffic on the web today that's not IE or Firefox. On mobile that comes very close to being all traffic, period. That means there's very little competition out there and that in turn leads to stagnation.
Some developers recently called out Apple for its lack of progress with Safari Mobile, including one developer who made the inevitable and apt comparison to IE: Safari is the new IE.
Regrettably, since Apple doesn't allow other browser rendering engines in the App Store there will never be any real competition there (there are other “browsers” in the App Store, but they all use the same WebKit rendering engine).
On the desktop and other mobile platforms, however, Edge just might give WebKit/Blink a much-needed kick in the pants.
If Edge can really beat Chrome, Microsoft has an opportunity to beat Google at its own game, namely making the web faster for everyone. ®