I think a CMS makes sense in some use cases, eg formal organisations, particularly those large enough to have some kind of in-house IT team. Does it make sense for a solo project, run by someone with the skills to build an efficient site from scratch to meet their needs (ie you)? It probably doesn't. Although there *might* still be advantages in sharing the maintenance headaches that emerge over time?
One cool thing about Ghost in particular is that if you use version 6.0 (once it's out), you can use the AP integration to make everything you publish natively available in the fediverse. I'd love to see this syndication engine tweaked so plugins can be added to publish over Nostr, ATProto, and any other protocol someone wants to write a plugin for.