You can just use FTP, and HTML/CSS, as the presenter claims, but if you want reusable components, you're going to need at least some-JavaScript based technology

You can just use FTP, and HTML/CSS, as the presenter claims, but if you want reusable components, you're going to need at least some-JavaScript based technology, like custom elements (web components). If you don't have a concept of a component, and every time a developer needs a simple component: a Button, a Link, a Card, pray that every single developer in your organization understands the accessible, semantically-correct way to implement it (spoiler alert: they won't, occasionally, a junior engineer won't understand why buttons shouldn't be implemented with <div> tags). And hopefully they follow your design team's specification for how the component should look (again, they won't). Then, you end up developing a product with ten disparate and interwoven look-and-feels, due to developers on separate projects re-inventing the wheel instead of using a common Design System. It no longer feels like one cohesive experience. The counter point: That JavaScript is actually solving enterprise grade problems-- controlling your brand via a Design System, ensuring accessible HTML gets generated, and so forth. It comes at a cost of potentially somewhat slower performance, but the solutions provided make the tradeoff worth it.