And? Most of these are things you absolutely should be thinking about
"You should be thinking about" and "You need this? Seriously?" are very different statements. Of course you should be aware of dependencies.
And you should also be aware of what it takes to rebuild your stack, and have something in place if that disappears. If you think it's OK to rely on external tools like that to build your system, you deserve all the fallout you get when it fails.
"Wait, you're telling me these people need an internet-available Ubuntu mirror to install their development environments?"
"Wait, you're telling me these people need their users to have specific, updated browsers in order to run the deployed software?"
"Wait, you're telling me these people need their users to have a patched, up-to-date operating system in order to run your desktop app?"
"Wait, you're telling me these people just assume users won't switch off their computers before saving changes?"
"Wait, you're telling me these people depend on the power grid being available to deploy?"
"Wait, you're telling me these people assume their users have fast, low-latency internet connections to play their real-time multiplayer game?"
You get the idea.