A focused engine vs an operating system
Ghost is a publishing machine: clean editor, newsletters and memberships native, fast by default, deliberately minimal. WordPress is everything-software: publishing plus commerce, courses, forums, directories, anything a plugin expresses. Comparing them is really asking: is your business the publication itself, or a website that publishes?
Ghost wins when
The product is writing (newsletters, analysis, membership publications), the workflow is editor to email to web, speed and simplicity are brand values, and the roadmap will not wander into commerce or community apps. Ghost's native memberships take a newsletter business from zero to revenue without a plugin in sight.
WordPress wins when
The publication is a channel, not the whole business: SEO at competitive scale (the deeper plugin and technical stack), custom content types, advertising systems, syndication, commerce of any kind, or organic growth as the primary acquisition channel. The price is the maintenance reality, updates, plugins, security, which a maintenance discipline handles but never deletes.
Memberships and email, both ways
Ghost: native, zero-assembly, opinionated. WordPress: MemberPress-class plugins or a stacked build (Stripe plus newsletter tool plus LMS), more power, more parts. For pure newsletter-membership plays, native wins on serenity; for monetization beyond subscriptions, assembly wins on ceiling.
The migration note
Ghost → WordPress is content-portable and routine; WordPress → Ghost works for pure-editorial sites and is honest when the answer is "your site is a blog, treat it like one". If the publication is the business, say so in one sentence, the recommendation tends to be fast and firm either way.