I’ve read through your various comments, and I’m not sure you see the difference here.
With other platforms such as Steam, you download the Steam program that acts as a single installer for every game on the platform. You have to be logged into a valid Steam account to download a game from their single installer. If you use a new computer, you have to log into Steam and download from Steam. On GoG, you download an installer per game. Those installers can be transferred to any device and download the games even if the computer has never logged into GoG or even connected to the internet. You can store all the installers on an external drive, which you can’t do for Steam.
If Steam eventually dies or your account is banned, you can never install those games again. If GoG eventually dies or your account is banned, you are correct that you can’t download new installers, but you can use any installer you have already downloaded.
If Steam dies or your account is banned, the game you already have downloaded may not even work anymore due to DRM (this is on a game-by-game basis). If GoG dies or your account is banned, your games are guaranteed to still run since they are not dependant on GoG DRM (with a small list of exceptions people aren’t happy about).
You may not care about any of this, but there’s a decent chunk of people who want to keep their games regardless of anything the purchasing company does.
I had to log back into an account for an app (I think Taco Bell) that decided to remove passwords entirely without any notice. You typed in your email address, had to open your email account and click a link they sent you, it would open a webpage, which would then have a button to open the app again. If I remember correctly too, it would only work on Chrome, so I had to copy and paste the link since Chrome isn’t my default browser that automatically opens from my mobile email.
Besides that, I remember some website required a special character from an extremely small list and wouldn’t allow two of the same letter back-to-back.