I too am a new Ubuntu Mate user. I am so impressed with this distro that I joined the community and searched out new user feedback so I could post my thanks and appreciate for this distro (like OP Jonathan_Bon did).
I currently work in tech and make a nice living with a career I have centered around Linux. I exclusively run Linux servers at home and at work. Desktop is a slightly different story. I am going to try not to beat up too much on Gnome 3, but I have really tried to use it over the decade+ since its release. I still find it extremely slow and counter-intuitive to what I am trying to do. Recently I got brand new hardware at home, and decided to try it again, first with Fedora 38, then with Ubuntu 22.04. I still find Gnome 3 very slow, some of the UI features not conducive to my workflow and I am subject to random crashes. After 12 years, I would expect this experience to be a lot better. Experiences like this primarily kept me off of the Linux desktop for quite a while. But, I keep coming back, hoping for a better experience.
After my recent frustrations, yet determined to find some variant desktop interface that was appreciated, user friendly, and somewhat modern, Ubuntu Mate kept popping up in my searches. So, I decided to give it a try. Seriously Ubuntu Mate team, thank you for this. I had forgotten how enjoyable that Gnome 2 style was to use. Additionally, Mate is so much faster that my Gnome 3 installs. I actually feel like I am no longer fighting my desktop, or having to go out of my way to get things done how I need or want them done.
Mate is not without its problems, as the OP pointed out, I ran into small issues here and there. But nothing was a show stopper, helpful Internet posts and a few post on these community forums got me back on track quickly. The desktop experience is just so much better than anything I have tried recently in the Linux world.
I really wanted Gnome 3 to succeed, as most of the mainstream Linux distros have embraced it. I just can't understand why it's not a bit "better" by now, given the the heavy hitters (RHEL, Canonical) that have thrown their weight behind it. I am hoping it gets there one day and it becomes a beneficial element for Linux, rather than something that still seems to divide the community a decade after its release. But for the foreseeable future, I will be running Ubuntu Mate as my desktop OS. Thanks again, guys. This is a truly enjoyable experience.