I can do almost anything I need with Web tech.
Desktop or even native mobile development seems to be like going back to the last century.
I'm doing a native mobile project next month, and looking at the stuff a iOS dev needs to get going is horrible.
The funny thing is that looking from the opposite perspective I feel the same. The web development looks like going back to beginnings of programming and reinventing everything again in the browser. You know, like when you read about 'tree shaking' being cutting edge technology in JavaScript land, then look at definition to realize that it's just dead code elimination that has been done by linkers & compilers for ages.
I don't know, maybe it just seems better to me, because I'm doing Web for so long now.
When I see desktop/mobile with Qt, Java or C#, I see huge IDEs, runtime environments and SDKs and with iOS even vendor lock-in, simulators and whatnot.
When I see Web with JavaScript, I see tiny editors, browsers that are already installed on every machine and bring all the SDKs and runtime environments, fast iterations, a good package system and general simplicity.
If you want to do mobile, try making it a PWA. If it needs to be in the app store (which these days I often see portrayed as more of a necessary evil than something desirable) go hybrid. If hybrid is too slow, try React Native or NativeScript. All of these can build on your existing knowledge of web technologies.
If you want a desktop app, you probably don't actually want a desktop app anyway, so just build a decent web app. If you need something that runs outside the browser, use Electron. Or React Windows if you only target the UWP.
If you want to build something on the server-side, there's of course Node.js. If you want something more tightly integrated with the database try ArangoDB. Again, same language you already know.
There are still niches where you need the raw performance of specialised programs written in other languages than JS, of course, but they are growing smaller. It's basic economics: if you can hire two full-stack JS devs instead of one iOS, Android, Windows and back-end dev each, you can cover the same technologies with half the salaries. This is especially true if the specialists end up doing mostly busy work because you don't actually need their specialised expertise all the time.
Few companies can afford to have all these dedicated specialists on the team but they may still want to cover multiple markets (e.g. an app for desktop and Android). In this case going for the web is the obvious choice for the smaller budget. The alternative would be hiring multiple contractors or outsourcing the project to a company that has the resources to provide all of the needed specialists all the time.
There are many ways to leverage your Web knowledge, you don't have to start from zero.
But it's still a chore to do mobile development.
I want to build a iOS app, because 80% of the potential customers are iPhone users, but in the future I want to use as much of the code on Android. So its Hybrid or React-Native.
So I thought, well Expo sounds nice, and gives me a Web like dev experience without the need to set up a Mac OS system.
Then I checked if they support AirPlay and HealthKit and the answer was "detach".
So now I'm back to "regular" React-Native and have to setup a Mac to get started.
Well, at least it seems running a dev VM for Mac OS isn't big of a deal anymore :\
Is it even possible to run macOS in a VM on non-Apple hardware with a non-macOS host yet? Microsoft provides free VM images for every OS and browser version you might want to test against, Google provides the Android devkit that works cross-platform. But if you want to target macOS or iOS it seems you're still stuck buying Apple hardware for $$$ to do anything. And don't even get me started on the lackluster support for PWAs -- at least the fallback for those is a web app that still works in the browser (provided you have Apple hardware to test it on).
EDIT: Also Microsoft has moved React Windows into its official GitHub org and advertises it as an official way to provide extensions to Office.
It seems like MS thinks their only way to win something in the "mobile war" is pushing PWAs.
And maybe they're right. Most people use the iTunes or Play Stores. They need to get devs off these platforms and show them that their tools are the way to go if you don't want pay taxes to Apple or Google.