WordPress gets a site live fast on a mature plugin ecosystem; a custom-built website trades that speed for performance, security, and functionality that isn't bent to fit someone else's plugin. Most small sites are fine on WordPress — fewer projects actually need custom code than the constant plugin-update cycle would suggest.
Start with WordPress if your site is primarily content and standard functionality — it's faster and cheaper to get live. Go custom when your requirements push past what plugins can cleanly deliver, or when performance and security need to be designed in rather than patched on top of a general-purpose CMS.
It can be, because a custom build only ships the code your pages actually need. WordPress performance varies widely — a lean, well-optimized WordPress site can outperform a poorly built custom one, but plugin-heavy WordPress sites are the more common source of slow load times.
WordPress itself is reasonably secure, but its attack surface grows with every plugin and theme you install — most real-world breaches trace back to outdated or vulnerable third-party code, not WordPress core. A custom site avoids that specific risk simply by not running third-party plugin code.
When your functionality needs are specific enough that you'd otherwise be stacking and configuring several plugins to approximate them, or when performance, security, or a particular data model are priorities that a general-purpose CMS makes harder to control.
Yes — content and structure can be exported and rebuilt on a custom stack. It's common to start on WordPress to validate a business idea, then move to custom development once specific requirements or scale outgrow what plugins can comfortably handle.
Not sure whether WordPress or a custom build fits your project? Tell us what you need and we'll recommend the right starting point.