This decision gets made on the wrong grounds constantly. Developers argue about technology. Business owners hear a lot of terminology and end up choosing based on which explanation sounded more confident.
The useful questions are simpler.
Who updates the site, and how often?
If your staff need to add pages, change prices or publish news without calling anyone, WordPress makes sense. That is what a content management system is for, and it does it well.
If the site changes rarely and you are content to send changes to a developer, a custom build removes an entire layer of complexity, cost and security exposure.
Does it need to do something, or show something?
A site that presents information — services, contact, portfolio, articles — is well served by WordPress. Plugins cover most standard requirements and the whole thing goes live faster.
A site with genuine application logic — user accounts, workflows, calculations, integration with another system — is often cleaner and cheaper to build directly. The school portal we built handles admission applications, status lookup, job listings and staff application tracking. Assembled from plugins, that would have been a fragile stack of parts fighting each other.
What is the ongoing burden?
WordPress needs maintenance: core updates, plugin updates, security monitoring, backups. That is real work and it costs real time or real money. Neglect it and a site gets compromised eventually — this is close to inevitable rather than merely possible.
A static custom build has almost no attack surface. There is no admin login to brute force and no plugin vulnerabilities to patch, because there are no plugins.
What about speed?
A well-built site is fast in either. A WordPress site with a heavy theme and thirty plugins is slow, and that is common enough to be the stereotype. But it is a symptom of how it was built, not what it was built with.
Static sites start faster by default because there is no database query and no server-side rendering between the request and the page.
The straightforward answer
WordPress when staff will edit content regularly, the site is largely informational, and you have someone to keep it maintained.
Custom when the site does something specific, changes rarely, or when security and speed matter more than day-to-day editability.
Most small businesses are genuinely better served by WordPress and are told otherwise by developers who prefer building from scratch. It is worth knowing which conversation you are in.