@Pawlicker No it isn't.

If you buy a computer with systemd/Linux Mint installed, then you won't need to run an installer, just like renting a computer with windows installed.

The windows installer is far, far worse than Mint's installer, as that terrible installer can fail in countless ways and give no clear error as to what failed during the install (it doesn't even have an option to erase x disk and install onto it - you need to manually remove all existing partions), while Mint's installer as shown at least states why the install failed (my only complaint is that it doesn't list the GRUB error output, although clicking the arrow to the left of "Running" should show it).

I primarily suspect user error, with manual partitioning incorrectly being carried out, resulting in GRUB not having a MBR block or FAT32 UEFI partition to install itself into, but need error output to know for sure.

As far as I can tell, once partitioning is fixed, GRUB is installed and a user account is manually added (via superadduser or a GUI tool), Mint will be bootable, or one can erase everything and start over.