For most service businesses: Squarespace/Wix-class builders if you want hands-off simplicity and can live within templates; WordPress if you want ownership, plugins, and portability at the cost of maintenance; custom only when a real application lives inside the site. The platform matters less than everyone pretends. Google ranks content and speed, not CMS brands.
Build-it-yourself works when your time is genuinely available and the bar is a clean five-page site; hire when every weekend for two months costs more than $3,000 of your billable time, or when it's still 'almost done' in month four.
Whichever path: the logins live in YOUR accounts, the domain stays at YOUR registrar, and the content can leave with you. Platform lock-in is the expensive part of every cheap decision.