If ARM comes anywhere close to viable enough to be "winning", there will be a good market for dev platforms, and somebody will step in and fill the need. Heck, some are even arguing here that the Pine64 already meets that need.
* New systems languages with promising levels of adoption
* Stablization and commodification of the existing platforms, weakening lock-in effects
* Emphasis on virtualization in contemporary server architectures
* "The browser is the OS" reaching its natural conclusion in the form of WASM, driving web devs towards systems languages
All of that produces an environment where development could become much more portable in a relatively short timeframe. It's the high friction of the full-service, C-based, multitasking development ecosystem that keeps systems development centralized within a few megaprojects like Linux. But what is actually needed for development is leaner than that, and the project of making these lower layers modernized, portable, and available to virtualization will have the inevitable effect of uprooting the tooling from its existing hardware dependencies, even when no one of the resulting environments does "as much" as a Linux box. The classic disruption story.
Why is this discussion so fixated on having a local development environment? It's 2019.
Right now ARM probably outnumbers x86 in number of machines running Linux by a very large margin. In my backpack there is one x86 machine and two ARM ones and that doesn't count the one that's in my hand
It all depends on what chips become available at what price. All cloud providers do lots of hardware design for their own metal. I'd they tell you that their next data center will be primarily ARM, they create a market for a million unit run of whatever CPU they choose.
As do the current top two supercomputers, Summit and Sierra, among others.
Having a cheap, viable ARM-native development platform drastically increases the chances of ARM-only killer apps to exist, this would be an advantage over the currently dominant x86 (just as there were Windows-only and Linux-only killer apps that cemented their ascent). However, if everyone is cross-compiling due to the cost, it means ARM will always be a secondary platform (at most)- it can't win by being the Windows Phone of platforms.
[edited for clarity]