I have been a long time Linux Mint user.
It was easy to install, nice to use, cinnamon is a great desktop and the applications are very stable as based on Ubuntu LTS. So why did I switch?
With the time I discovered TILING WINDOW MANAGERS like i3 or my favorite HERBSTLUFTWM.
As I have a big 43" 4k display, a tiling window manager works very great. Herbstluftwm even goes deeper and allows to split the monitor in different "virtual" monitors, where full screen applications for example don't expand over the given virtual monitor size. I used dzen2, then lemonbar / barpyrus and in the end switched to the great polybar.
And this is where Manjaro comes in.
To get the latest and greatest version of Herbstluftwm which supports single floating windows or to get the polybar without the need to wait two years, I had to build these applications my self. This was time consuming and bad.
Then I discovered that there is Arch Linux, but it is harder to install then Manjaro and doesn't have much preinstalled applications or a desktop. But Manjaro is easy to install, has some preinstalled things and comes with three desktop to chose from: Gnome, Xfce, Kde.
I sometimes use a desktop environment when something is broken in my configs for herbstluftwm etc. I like it more than using a tty as I find it easier and better to use as fallback.
Manjaro has always the latest and greatest applications via the official repos or AUR. I can also use Snap or Flatpak without issues. Pamac is a software store ui that has flatpaks, AUR, official repos and snaps at the same place with the same install procedure. Something I searched on my Mint for months. I always had mint-install, gnome-software and synaptic.
Installing apps is just so much better to use and Debian, which Mint uses as a backend ( yes it uses Ubuntu but Ubuntu is based of Debian ), did some weird and non acceptable decisions like kicking out Norbert Preining who helped Debian a lot and did nothing wrong in my opinion. Cause that we should leave Debian as fast as possible.
Updates are also easy to make on Arch / Manjaro. Everything works fine and Firefox has some cool skinning.
Zsh also has a great preconfig. I used Zsh on Linux Mint some time ago but didn't had time to configure it so I switched back to bash. Picom is also easy to install just from the software center pamac.