zlacker

The general problem is that there are some APIs which work differently enough between platforms that they leak sufficiently that it makes a difference above the stuff they're supposed to abstract. The browser is [sadly] as close as we've been in recent history to having APIs which mostly work across platforms by leveraging the browser (which is consequently made by the OS developers on mobile OSes) for abstraction over OS stuff. Combined with how "everything is in the cloud" and the decline of the importance of stuff like local file management for average users (now you can lose all your stuff in GDrive just as easily), it's becoming a good-enough choice for making software that works on whatever thing people try to run it on.

Java on a phone is nothing new, but the Java for Symbian you'd write probably wouldn't work very well on a desktop. VC++ for Windows Mobile apps wouldn't work well on a desktop either. The web is the lowest common target, even though it's quite a high level to target. We still run into plenty of HCI issues (why is there a big fat + button in the lower-right on my laptop in GDocs instead of "New" or File -> New action? Because Material is mobile-first and applied thoughtlessly to non-touch experiences), but if you play your cards right, it's now possible to have a codebase, and truly the same app, running on whatever OS and architecture the user has, without specifically building and packaging for 30 different target combinations.