On windows, you have to go to the software's website, find the download page, click download, run the installer exe, then click through the installation wizard.
On Linux, you can either install it in one command in the terminal, or install in one click from a gui. You almost certainly have a gui app store preinstalled unless you choose a minimal distro like Arch.
If you want to update software on Windows, you go through that whole process again. On Linux, you just do a system update.
I'm not really sure what part of that is easier on Windows
Or you could use a gui that is probably already on your system, like I said. Maybe Ubuntu just sucks, I don't have experience with it. But I have used flatpak on SteamOS, which is incredibly easy and smooth.
But the terminal can be super easy too, it's not like you're typing out complicated commands just to install software. I use yay, so it's literally just 'yay ' to search and install.
Just because you are already used to Windows doesn't mean it's simple. It's actually more convoluted and difficult to learn if someone hasn't used either.