From Why Client Side Rendering Won:
- No Full Page Reload Required
- Lazy Loading
- Rich Interactions
- Cheap Hosting
- Use a CDN
- Easy Deployments
- Enforced Separation of Concerns
- Learn Once, Write Everywhere
- Same UI Technology for Web, Native Mobile, and Desktop
- So. Much. Free.
My personal additions:
- Tighter Development Feedback Loop
- Reduced indirection, simpler to reason about
- Response to Unreliable internet connections, more capable client devices
- Leverage client resources to minimize server resources
- Faster response makes for greater usability