feat(ipip-0499): document efficiency benefits of modern profile parameters

add user benefit explaining why 1 MiB chunks with 1024 links per node
results in shallower DAG trees, fewer total nodes, faster seeking,
and reduced DHT announcement overhead compared to legacy 256 KiB/174 params

Author: lidel

src/ipips/ipip-0499.md

@@ -170,14 +170,20 @@ This profile documents the default UnixFS DAG construction parameters used by Ku
 
 ### User benefit
 
-Profiles provide 3 key advantages for working with content-addressed data:
+Profiles provide key advantages for working with content-addressed data:
 
 1. **Predictable, deterministic behavior:** Profiles restore intuitive hash-like behavior: identical input data always produces identical CIDs, regardless of which implementation generates them.
 
 2. **Lightweight verification:** Users can verify content without needing to rely on additional merkle proofs or CAR files.
 
 3. **Simplified workflow:** Users can select a profile and automatically get consistent CIDs across all implementations, without needing to configure or understand the underlying parameters.
 
+4. **Improved efficiency:** The `unixfs-v1-2025` profile uses 1 MiB chunks with 1024 links per node, compared to the legacy 256 KiB chunks with 174 links. This results in:
+   - Shallower DAG trees (3 levels for a 1 TiB file vs 4 levels with legacy parameters)
+   - Approximately 4x fewer total nodes for the same content
+   - Faster random access and seeking in large files (fewer round-trips to traverse the tree)
+   - Fewer CIDs to announce, reducing stress on public good routing infrastructure such as the Amino DHT
+
 ### Compatibility
 
 UnixFS data encoded with the CID profiles defined in this IPIP remains fully compatible with existing implementations, since it conforms to the [UnixFS specification](https://specs.ipfs.tech/unixfs/).