Updates have disappeared because most software today is no longer full offline (as was the case of those CD-ROMs you’d use to install softwares back in the days), but a hybrid of offline and online, with a local client making calls to an API. A software company can’t ship a hybrid product and stop running the API, the API has to be kept up, which is often no small feat, and costs money. On top of that, if they had to deploy different endpoints for different versions of the client, the backend management would become absolutely chaotic and cost the company even more.

Tldr: online softwares cost money to run, even after they’re sold. They’re not standalone softwares.