What if there was no open-source software

I was listening to a podcast today, and the question was mentioned - "What if there was no open-source software?".

As a self-taught Developer who has worked with open-source technologies and become an expert in Drupal - an open-source content management system - this would have had a big effect.

If there were no open-source frameworks or CMSes like Drupal, Symfony, Laravel or Vue.js, Developers would need to write everything from scratch, and companies would need to pay for the extra time.

There would be no reusable knowledge as Developers move to different companies as everything would be written in-house.

There would be no communities and events like conferences and meetups for open-source technologies.

As well as frameworks, what about languages like PHP that are open-sourced? Would companies also need to write and maintain their own programming languages?

What about Linux, which I use every day for my desktop environment and servers, and other tools like Neovim, PHPStan, PHPUnit and Pest that are all open-source?

Even as someone who contributes to and sponsors open-source projects and their Developers, it's still a shock to think how things would work without open-source software.

If you use open-source software, please consider sponsoring, supporting or contributing to the projects you use and depend on.