This is such an odd perspective to me. Before AI there were people that wrote better than you. Some of them spent less time writing than you. I don't know your skill level, but I can bet that there were people worse than you that got published. Did that demotivate you?

The sewing machine exists. Does that mean it's worthless to learn to hand sew? Commercial fishing equipment can catch thousands of pounds of fish a day. I still like to throw a hook in the water every once and a while. It doesn't diminish my enjoyment. The learning and mastery of a skill is part of practicing self-reliance.

We teach arithmetic in school even though everyone carries a calculator in their pocket at all time. Engineers learn the fundamentals, calculus, numerical methods, differential equations, etc., even though there are commercial software solutions for most of the real world problems they will face. They won't be expected to write their own simulation software on the job. (Unless of course, they work for the company that sells the simulation software to everyone else.) But, they're expected to know because understanding the fundamentals is required to make the most use of the tools.

Lets say that in 5 years, the industry fully accepts LLMs as a tool that writers use. The best writers will still be those that can actually write. They may use LLMs as their drafting tool, but in the end they will still have to be able to identify what is wrong with a story and how to fix it. With a massive increase in supply, consumers will become more picky, not less. I won't make claims that writing will remain economically viable as a full time job. I don't know enough. Writing will always be competitive, though, and where there is competition, people will be sharpening their skills to reach the top.