Similar to iOS, M1 macs also have the feature that allows you to restore your faulty device using a downloaded IPSW file. You have to put your Mac in DFU mode and download the Apple Configurator app to perform the recovery. Connect the M1 mac to another Mac, run the Apple configurator, and drag and drop the macOS IPSW file to start the offline restore process. The complete set of instructions for reviving and restoring your M series Mac using the IPSW file is presented on the Apple website.
You don't need a bootable installer to upgrade macOS or reinstall macOS, but it can be useful if you want to install macOS on multiple computers without downloading the installer each time, or you're unable to install a compatible macOS from the Finder or macOS Recovery.
Another option is to peruse the Apple Vintage Software collection at Archive.org which may have image files of older system restore disks and other older system software, just beware that archive.org is not an official distributor of Apple software so appropriate precautions should be taken and only download from there at your own risk.
This happens primarily because of the high volume of traffic hitting the Apple servers, which causes congestion in the network. And the situation would probably remain the same, at least for the first few days. I remember wasting around 15 GB of data trying to download OS X El Capitan last year.
To verify the setup, open any of the package URLs (.pkg or .pfpkg) in your browser and check the download speed as it downloads the package. You should notice a very high speed which is much higher than the speed of your Internet connection. This is because the file is being downloaded from localhost. Your Internet bandwidth is not being used.
When I try to get the High Sierra or Mojave installers, the link takes me to a page where the link only takes me to the app store where those installers do not appear anywhere that I can see. The links for El Capitan, Sierra, and Yosemite got me to a page where I could download a dmg so those seem to work.
As others have noted High Sierra and Mojave are obtained via the App Store. I am still using El Capitan but had older copies of High Sierra and Mojave stored on my computer for future consideration. The App Store wanted to open these copies so I had to trash them before the updated copies would download.
I got them all to download, except High Sierra. On the app store page for HS I got an Open button, even though I had unmounted my archive volume that contained the HS installer. So I used the macOS High Sierra Patcher tool as you directed, getting the installer download instruction from the Tools menu. Great app. High Sierra was them downloaded to my specified location. So now I have updated apps for all the macOS X installers in your list. However, this was the only one, besides Mojave, that downloaded the app. The other links downloaded dmg copies, which do not contain the usual installer app. So I retained the apps for Mojave, El Capitan and Yosemite.
Before downloading the standalone dmg file of iMovie, you should try to upgrade iMovie to the last compatible version automatically on Mac's App Store. This will work if you have or ever have had iMovie 10 on your Mac. Here is how: drag your iMovie 10 app from the Applications folder into the Trash, but do not empty the Trash. Then launch your App Store, login your account, open your purchases folder by clicking on your name at the bottom of the app store side bar, then find iMovie and try to redownload iMovie to your Mac. If the following dialogue appears, click Download to start installing the last compatible version of iMovie to your Mac. If not successful, drag your present iMovie app back to the Applications folder.
But creating a bootable USB disk allows you to install or update macOS on multiple systems without having to download the installer on each Mac. This can save quite a bit of time, considering the most recent versions of macOS have an installer size of 12GB.
You can create a fresh installation of macOS, restore from a Time Machine backup, or access tools like Disk Utility from the macOS Recovery screen. You can also use your USB drive to upgrade macOS to the latest version. If you need to troubleshoot your Mac without a network connection, this USB drive could be a lifesaver.
Internet restores are notoriously flacky, and should not be depended on. If you can restore your drive, you should download a copy of the desired version of the macOS. It will land in your applications folder. You can run the installer from there and erase your drive if you want to do a clean install.
You will not find El Capitan download link available on the regular app store so you will have to go to the following link on the official apple website and then scroll down to step 4 and download El Capitan.
Before proceeding to downloading and installing the Mac OS Mojave 10.14.1 on your computer, backup all your data. It is important to do so because installing the OS without a backup can sometimes cause data loss and to be safe, backing up files on your system is important.
Note: A content folder owned by root is also created, which was used by the script to store the various downloaded components. If desired, this folder may be discarded once the disk image has been created. 153554b96e