As described before, go with your requirements. For real-world decisions:
Go static if your content rarely changes and you want simplicity, fast loading, and a lower cost. Great for personal bios, portfolios, documentation, small business info pages, or simple event sites.
Choose dynamic if the site needs to update frequently, interact with users, or store data; like blogs with login accounts, online shops, news feeds, or anything where the content is different for different people or changes often. Dynamic sites use server-side languages (like PHP, Python, Node.js) and databases to make that happen.
Some bigger projects even mix both: static pages for parts that don’t change, and dynamic pages where personalization or real-time data matters.