FydeOS is described as 'Offers a choice for regular PCs to behave like Chromebooks with alternative supporting services, on-premise or in the cloud, with or without Google. Formerly known as "Flint OS"' and is a Linux Distro in the os & utilities category. There are more than 100 alternatives to FydeOS for a variety of platforms, including Linux, Self-Hosted, BSD, Windows and Mac apps. The best FydeOS alternative is Linux Mint, which is both free and Open Source. Other great apps like FydeOS are Debian, Fedora, openSUSE and Manjaro Linux.
FydeOS is a ChromiumOS-Distrbution not a Linux-Distribution - ChromiumOS is based on a Linux-Kernel but is heavily modified - Linux Mint is a GNU OS running a generic Upstream-Linux-Kernel. They both share as much as OS/2 and Windows 10.