I do use Ventoy, but a more "traditional" alternative that I like is Popsicle. Super lightweight, and works very well. Some cases do require a dedicated USB, where Ventoy won't work, at least not without trickery (e.g. anything with persistent storage).
I've used ventoy to set up a bootable USB with Mint & MX options. It allowed me to set the Mint with persistence. The MX has issues with persistence.
How to set up reusable boot with dd I don't know.
Another program that works on Windows, which I prefer to Balena Etcher, but less so than Rufus: unetbootin
I curious because I don't have the skill to test it myself but can you just manually copy everything to USB it's just work?
In the general case, no, but there are some rare specific cases where that does work.
If you're trying to produce Linux media that will boot on a single-board computer that has an onboard bootloader, like a Pi 4, you can indeed just partition the target medium and copy the files manually (been there, done that, working with a custom Gentoo install with no ISO).
If the bootloader has to be on the target medium (as it would for a desktop or laptop), then that won't work unless you also do a manual bootloader install after copying everything. Not impossible, but at that point you're hitting the level of complexity where it's easier to figure out the correct dd command.
(As for Windows? Don't even bother. It hates being worked on with anything but its own tools.)
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Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution (or distro for short).
Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.
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