Instead of everybody having to create their own screwdrivers prior to starting a construction job, they can focus on building whatever they want to build.
I would argue that's a good thing: it increases productivity and decreases duplicated effort.
It still takes engineers to use the frameworks even if they are open source.
I think open source and the web have created more jobs rather than reducing them.
With open source you can learn from existing projects, pull in projects to your work to save time.
This time savings can be used to create and improve other custom features in what you are building.
If anything I would say open source is creating jobs and empowering developers to learn new techniques, create better apps and level up in knowledge and earning power.
I think it's also allowing people to get in to programming that wouldn't have a chance otherwise if you had to pay for every framemork/tool you wanted to use so open source creating more opportunities than it's reducing.
And open source can be a full time job. https://calebporzio.com/i-just-hit-dollar-100000yr-on-github...
I think open source is great for the industry/world.
So many amazing frameworks, tools, packages out there.
Kudos to everyone who maintains an open source project.
Today, it would have been a lot easier to do the same startup. We would have made more money, hired more people, paid above market average.
The goal of a business is to just focus on whatever they built and reach out to as many people as possible. Netflix does one thing. They don't build their own DRM or CA. They also pay the highest salaries in the range where possible. Maybe there would have been more Netflix jobs if one component wasn't done or if they had to build their own browsers. But they likely wouldn't have scaled as big or made as much profit, and would have been cutting salaries or reluctant to hire, trying to compete with something like HBO.
React is another example. Now there are countless React jobs instead of people using HTML+jQuery to build the same things. Has it increased productivity? It probably has, else why would people use it. But it's opened even more jobs.
Software is just never done. There's always more features to add and refine, more wealth to create.