Yes, you are right.
My concern is the addition of too many dependencies adding no QT-specific software.
For example, I don’t like the actual task manager, qps and I prefer the simplicity and the clarity that LXtask has.
(I have to admit that effectively I installed LXtask on Lubuntu 20.04, but it’s a secret between us ).
I am also personally fond to Gdebi and Synaptics (and I miss them a lot), but I would like to limit myself to install packages more specific to my distro and its DE, that in this case is actually QT-related.
Webcam software: if you have to prepare a videotutorial or a remote lesson for students, they are very useful since you can prepare the material being offline. If you remotely work in a school or in a company, due to this Coronavirus period, those kind of softwares are essentials and with Lubuntu 20.04 you have to look for by yourself. Nothing dramatic, but it would be more comfortable to have at least one choice already installed.