OP wasn’t talking about copyright, but was instead complaining that companies are never publishing their software at all, and are instead hosting their software

OP wasn’t talking about copyright, but was instead complaining that companies are never publishing their software at all, and are instead hosting their software as services on the Internet. Ownership of web applications is not governed primarily by copyright law (which is only relevant as it pertains to the front-end portion of a web app that users download to their browser), but rather by trade secret law (with regards to the server-side code) and trademark law (with regards to the domain name). Neither trade secrets nor trademarks ever expire if the proper precautions are taken—nor have they ever. Your point regarding copyright extensions is largely irrelevant to the question of web applications.