Do those apps that 14 year olds work on require an in depth understanding of how threads work? How different hardware components work together at scale? Most people with CS degrees never acquire the skillset to do such work, why should I believe that those who are trained via job training programs will be able to do so. I'd be more afraid of potential retraining of other highly skilled workers who want to switch careers than anything else.
The skillset of building a personal website, or even a website for your small business should be something anyone can do, and will in no way impact the overall salary of software engineers in the future.
Major companies will always need people who understand the computational sciences, as scale and complexity follow some of the same rules as entropy, in that they are always increasing.
Additionally, the reason for high salaries is not a lack of engineers, it is that top companies have decided that it is in their best interest to outbid each other for top talent. In parts of the midwest, where there is less competition, engineers are already paid 50k a year.