Once upon a time, a person with a variety of skills could find permanent, full-time work using many of those skills.
Every day was predictable, even boring, but being able to do a variety of things made life tolerable, and even pleasant at times.
One day, businesses that were formerly reluctant to stray from their trusted vendors began embracing open source software in general — and the internet in particular.
Because of that, hardware and software evolved more and more quickly, and everyone began expecting free access to increasingly sophisticated technology.
Because of that, the skills needed to develop this technology became extremely complicated, highly specialized, and very volatile. Companies found it increasingly difficult to hire permanent, full-time people with the desired combination of skills, and tech workers struggled to figure out which new technology was best to learn next.
Until finally, it became more realistic for a person with a variety of skills — such as myself — to seek a variety of part-time jobs rather than permanent, full-time work.