There are projects for which CD is not a good idea - projects where financial or physical harm may come to someone if a mistake goes out - but in my experience the majority of projects don't fit that definition.

Also, the great thing about CD is that mistakes can be fixed really quickly: push another commit.

Not using CD is no guarantee that you will ship less bugs. In fact I'd argue that it makes shipping bugs more likely, because the friction involved in deploying means you'll bunch up multiple changes in a single release - and that's a great way to discover bad interactions between changes too late.

(Even if you don't use CD to production, having CD to a staging environment is a no-brainer in my opinion: giving everyone on the team access to a current demo of the main branch is another big productivity boost.)