Off the top of my head I can think of the following fields that have a growing need software engineers; gaming, AI, data science, robotics, agrictech, virtual reality, health, cosmology, edutech, cybersecurity, IoT (Internet of things), SaaS (software as a service). While demand is expected to grow as a result of the above we cannot forget that engineers will still be needed to maintain and extend the current infrastructure we have (which is a lot).
When people worry that the salaries and perks software engineers enjoy won't last as the market will become saturated I'm somewhat baffled. I believe the salary isn't a tenth of what it will become in the near future as innovation grows. Uninformed individuals are worried about programming languages and frameworks, using such things to predict software engineers losing jobs if a certain language is disrupted, software engineers are unbothered, we don't worry about languages, we monitor technologies.
It takes averagely a year to get a masters degree. In half that time a software engineer can selfstudy and migrate to any of the field I mentioned and be employable, those fields above aren't distant relatives like you would compare a doctor and a lawyer. For software engineers, it's more like switching from being a midfielder to a striker or vice versa. The only way demand for software engineers will dip is if the global economy collapses and we head back to the stone age.
While some worry about automation of software engineering jobs, just like 3D printing, the expectations will differ from the reality because one would still require some technical level of expertise to command AI to perform certain automated tasks. A lot of times, software engineers assist clients in determining what they truly want. Just like a lot of people don't know how to properly search the web (and aren't aware of the fact that they don't know), I believe there will be a lot of blunders that will occur if unguided by software engineering.
There is no reason not to believe that as innovation and value creation rises in other sectors, the demand for software engineers will equally rise, tech isn't really a sector on it own at this point, it's pillar that supports every other sector. The value that software engineers deliver to other sectors justifies their handsome salary and that is said to increase as mankind begins to attempt more herculean feats. Any software engineer with an open mind will always have food on the table.