I know this will come as a shock to a lot of people, but a lot of software doesn’t do CI/CD. Especially CD. Basically only webapps can do CD, although Dropbox is close with weekly releases. A lot of enterprise and industry software still does quarterly or even semiannual releases. Hospitals, banks, and government agencies in particular have stringent vetting procedures that mean they can spend months verifying and approving a new major version before upgrading, so there’s no point throwing one at them every couple weeks.
If you’re random Joe Schmoe who happens to need a database, I don’t expect you to contribute. But when you’re of the largest tech firms in the world…