When you import pictures, you have to select the 'Lightroom' folder as destination in the Import dialog. You didn't do that recently; you selected the 'Afbeeldingen' folder.
This is easy to solve. First, right-click on any one of the 2006 - 2019 folders in the Lightroom folder panel and choose 'Show Parent Folder'. That will show the 'Lightroom' folder in the folder panel. Then drag & drop the '2021' folder into the 'Lightroom' folder in that panel. This will also move the folder in the Finder. The second '2020' folder is a bit more complicated, because it already exists at the correct location. So for that folder you'll have to drag & drop the individual subfolders. When you have done that, you can right-click the empty '2020' and choose to remove it.