Hi @toofeak ,
>>>>I say it's a problem because in the oficial support and learning page of Dynamic Layer group, it says it can be removed
Indeed, any Dynamic Layer group can be deleted. The Help topic is correct.
Try create new Dynamic Layer group in the drawing you shared:

Now link at the Layers palette:

Another thing is the automatic layer group. It cannot be deleted because it is created automatically. But you can easily turn off its display in the list of layers (see my post above).
>>>>>It bother me because it make new groups and change my layers order when i create new layers
As I wrote before - you can turn off Automatic Layer Groups.
>>>>>This is in a file of a city map that i found on internet and it already have a massive list of layers because it have a massive list of automatic grouping rules and come from the binding of severals xrefs.
They are not Automatic Layer Groups - they were created during drawing lifecycle by users. Try it - You can remove any of these groups in your drawing.
If you need Layer Groups, but don't want to see them in the Layers Palette - you can turn off them in the Palette:

If you don't need them - delete them:
- turn on "Show Groups on the bottom" to find first group easily
- select the first group
- scroll to the end of the layers list and select the last item in it
- all groups will be selected
- right-click on the last group and select "delete group" - all groups will be deleted.