Why do so many software authors insist on forcing their users to do pointless busywork when updating their software?

A lot of software, such as Notepad++, pgAdmin 4 and Bisq, which are all open source and free of charge, with no attempts to install malware/spying in the installer, make it needlessly annoying to update them.

Instead of just seeing a message such as:

There is a new version available: 1.2.3. You are currently running 1.2.2. Update now? [Yes] [No]

And then just update itself when pressing "Yes"...

They instead nag you about an update being available, but when you accept, it either downloads a new installer or even just loads a webpage where you have to manually download the installer. Either way, once you run this new installer, it treats you as a "first-time customer", as if it were the initial installation, making you look at a GUI and manually click "next" multiple times for seemingly no reason.

Why would it not, since it already is installed on the computer, detect this (or launch itself with a flag such as "/update") and just update instead of showing the pointless GUI installer stuff which I already went through when originally installing the software?

For software developed by scummy companies, the reason is obvious: they get another chance at tricking you into forgetting to disable their toolbars/spyware/malware by having the checkbox pre-checked again. However, I'm again talking about these FOSS programs which don't use such tactics.

There is no logical or technical reason for this that I can possibly think of. It's as if they "punish" the user by making us do pointless busywork to waste our time and energy. Having been put through this for 20+ years, I'm absolutely exhausted from manually dealing with update after update after update, and I cannot believe that they haven't automated this very obvious and simple thing after so long, instead putting their users through it again and again.

This practice heavily discourages updating, and I've many times stuck to old versions for a very long time just because I can't deal with clicking through another pointless installer.

And no, I don't want to use and trust some third-party "Chocolatey" software. I'm asking why the actual developers of software do this.

And no, this doesn't take any more work in any way for the developers. Again, I'm talking about how the installer shows itself and makes me go through pointless steps for no reason since the software is already installed, and all the installer ends up doing is just copying over the new files to my existing installation dir. There is zero reason for it to do this, because the software is already installed and it clearly knows what to do already since I can just click "next" multiple times and then it updates.

The problem is that the installer shows that nonsense at all, since it's an update and not a "fresh installation".

Why do they insist on doing this?