!. Both mobile and desktop devices are getting faster every year. More memory, faster processors, better GPU.
3. HTML5 specs don't change once they have been agreed upon.
4. The field is narrowing. Chrome, Edge, Safari. But the largest percentage are using Chrome and will only increase.
After spending two years trying to keep up with yearly changes on iOS, Android, and Unity, I've given up on them. The mood of those engines seems to be break things and run away fast.
So learn Construct 3 and let Ashley worry about changes in the exported platforms!
And after a few weeks playing with Construct 3, I can say that most of it operates the same way except that:
1. You can now do your coding on PC, Mac, Android, and Chromebooks. Use the cloud and you can code on a different machine every day.
2. Most of the mechanics seem the same. The only thing I'm noticing so far is that we can now use booleans, which are nice.
3. I'm noticing lots of little things that make stuff easier. Lots of little tweaks.