I just upgraded to 26.04 and had to spend some time researching and messing around before I found out a specific package was missing which solved my problems. That package is gnome-shell-ubuntu-extensions!
So yea, after installing that package (with apt) and logging out and back in again, I opened the gnome extensions manager app/thing, and saw desktop icons NG, Ubuntu Appindicators, Tiling Assistant & Dock extensions are all present.
Just thought I’d make this post so that in the off chance someone has the same issue and looks for the solution on lemmy, they can see this and know the solution?
Just now, I wanted to add that as an edit of my post instead of adding it as a comment, but this website kept giving me a error message stating “language not supported”. Then I changed the language from “select language” to “undetermined”, but the dropdown selector kept instantly resetting itself!