Welcome to the Ubuntu Discourse, @mike2thel54!
OP’s issues has nothing to do with the removed GUI and Canonical’s reasoning for doing so are very sound, as always:
Plus, OP is using Lubuntu, so shouldn’t even notice that particular change.
What’s even more interesting, is, that “Software & Updates” can still be installed from plain old Ubuntu sources 
:
sudo apt install software-properties-gtk
I think you have some kind of latent hostility towards Canonical, probably borne from some “bad press” from some shady actors on the Internet. These changes are all in the name of the best possible UX, especially for total novice users. It has been said more than once that Ubuntu is akin to MacOS in the Linux world:
Do watch that video to the end, if you don’t believe the MacOS quote. I can go as far back as Ubuntu Unity which first gave me a real sense of a MacOS experience, only better. But “the internet” didn’t like it, so it had to die. 
Yes, it still hurts. And no, the Unity flavor alone won’t cut it for me.