No it does not.
First of all, everything on a computer and according devices boils down to ones and zeros. Files and directories. It’s all human-made applications. So is an operating system and so is the according installer. Bootable just means, there is an application that’s called a boot loader, that tells the BIOS, where to go next. From there it starts the next application.
What it starts, could be anything. It could a rescue disk, a partitioning application, a Linux live system or an installer for an operating system.
An installer just overwriting you data would be dangerous and detrimental in most cases. So, operating system installers usually don’t just overwrite your data and setup. They will ask you for certain settings. Like where you want to install the operating system, language settings and so forth.
Next to that, these days operating system media are likely mixed media and don’t just serve one purpose only. For example, Linux often comes with a live system, which you could use for all kinds of stuff. Windows for example comes with a few repair options on the install medium.
So, running into a medium that would install an operating system right away without asking would not be impossible but would definitely be a rare exception and either created for a specific purpose, like for example mass installation for computer vendors and sellers, or considered malware and created by a cracker.
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