I was like “nothing wrong here” until I saw that T that my brain just refused to parse the first time.

You lost me here. What is noctalia, dankmaterialshell and dms? :D

Nice “desktop shell” projects that you can install in addition to your wm of choice to get all the stuff that you expect from a DE without having to set it up manually. Otherwise since a wm comes with nothing but window management you’ve got to go the traditional route of picking up a bar, an app launcher, a screen locker, a widget to connect to wifi and plenty of other things to have a decent experience out of your wm. With noctalia or dankmaterialshell (dms is just the short way to write it) you don’t spend a week setting everything up to then be sad it’s not as pretty as what people do on unixporn.

I use niri, I don’t know if it’s ressource demanding or not but the readme seems to say it works fine on old computers:

Performance: while I run niri on beefy machines, I try to stay conscious of performance. I’ve seen someone use it fine on an Eee PC 900 from 2008, of all things.

Regarding eye candy it’s also very sober by default, it can do animations, blur and transparency but you have to ask for it in conf.

It looks like a window manager for the younger generation.

I use it because It’s a nice middle ground between traditionnal wms and tiling ones. No messy stacking windows, no need to think too much about the layout, plus you get a larger screen than everyone at no cost :)

with the caveat that it’s lighter because it does less stuff for you by default

There are very nice looking things like noctalia or dankmaterialshell that can take care of everything for you (dms in particular), including bar/dock/niri conf/wifi etc. It’s much easier to have something functional and nice looking than before (including with other wms like sway).

You’ve got some companies advertising with streamers/youtubers that do some checks on who they advertise with. They use specialised communication agencies, it’s their job.

This looks like to me that you might have flatpaks installed in your home on the second laptop, while all your flatpaks must be installed system wide on the first one.

You can see what is installed system or user side with

flatpak --user list
flatpak --system list

As for the additional directories purpose, app contains the apps (surprising i know), runtime the runtimes needed by the apps (such as say the org.kde.Platform for kde apps etc), exports the things that are exported for integration (like a bin dir you can add to PATH or the applications dir containing the .desktop files to launch apps from the desktop etc. appstream is a metadata format about apps i’m not sure exactly what they put in that dir, some cache maybe ?