Are writing careers a good election for the future? Which are some writing careers with more future growth?

Fiction: no. Only 5% of all fiction writers make a living from it. That has not changed in the 30 years I have been writing.

Nonfiction: no. Maybe 10% of all nonfiction writers make a living from it. That also has not changed.

Technical writing: yes. However, you need to already be proficient in what you are writing about in order to get a technical writing job.

Writing ad-copy: yes. But the jobs are few and hard to get. On the plus side, they are generally real jobs, with salaries and benefits.