MichelDwo I deactivated the dock, I like to have everything in one taskbar at the top of my screen
I felt very much the same way when I first installed Xfce, because I had never gotten used to a dock before. It seemed to me that it was redundant, and simply took the place of the task list, but I came to realize that it does have merit. Because of the way it hides and shows itself "intelligently," by default, it's there when you want to see it and not in the way when you don't. The upper panel is very thin, by default, and with the hiding dock, the result is slightly more screen area than I was used to.
I'm a big fan of multiple workspaces. My VMs all have 8 of them, my laptop and workstation 10. Thus each application I normally use has its own desktop to run on, and doesn't need to compete with any other application. Email, Browser, File Manager, Terminal, etc. Over the years I've installed them in the same order from left to right, and that's what I've done with the dock.
So, I have the workspace switcher applet in the top panel, with 8 places where I run applications, and the dock at the bottom, which comes and goes according to when I need it, that decides which application to run. No need for a task list, so no redundancy. I've gotten used to that now in Xfce, and even installed a Latte dock on my Plasma laptop for a while.
What I couldn't get used to yet is the panel at the top of the screen. That's one reason I never cared much for GNOME, and I've almost gotten to think of it as normal in Xfce. As a GNOME user to start with, that should be very comfortable for you. The dock too -- I'm surprised you got rid of it.
I think I might even try that arrangement on my laptop again for a while. Maybe I just didn't give it enough time when I tried it before. And if it still doesn't work well for me, it only takes less than a minute to move everything back to where it was before.