Can you comprehend the idea that “serious work” for you is different from “serious work” for someone else? You seem to be assuming that everyone else works exactly the same way as you do, which makes your entire argument anecdotal. If you’re self-aware enough to admit that you don’t do drawing or photo editing on a computer, then it seems like you could make that mental leap to realize that maybe not everyone’s “serious work” is the same as yours.
Your logic is flawed: Many people don’t have desktop computers, therefore a tablet will be your primary device?? That doesn’t follow. Many people also have desktop computers at home that aren’t for gaming, or have a laptop that they can use at home but don’t want to carry everywhere. So yes, there are plenty of scenarios where your tablet isn’t your primary device.
…based on your specific use case, which you assume applies to everyone else in the world. The limitations you see are simply not there for other people. I mean, I illustrated an entire children’s book entirely on an iPad, but what do I know?? I must be a casual user, because my “serious work” isn’t exactly the same as yours.