JSX is 'just' an XML-like syntactic sugar for making nesting function calls nicer in Javascript. Yes, its a DSL, but it keeps the "domain" extremely small and it transpiles in a very straightforward way down plain javascript

    <Container>
      <Text weight="bold">madeofpalk</Text>
      <Image src={profilePic} />
    </Container>
    
    // is syntactic sugar for
    React.createElement(Container, null,
      React.createElement(Text, { weight: "bold" }, "madeofpalk"),
      React.createElement(Image, { src: profilePic })
    );

Whenever you need 'logic', you just escape out to javascript with braces

    <Container>
      { isVerified ? <Tick /> : null }
      <Text weight="bold">madeofpalk</Text>
      <Image src={profilePic} />
    </Container>

JSX has no conditional syntax, no ternaries or any extra constructs apart from how to nest children. This is I think a simplicity that would have been nicer to see in SwiftUI.