People used to say the same about Linux ext4, it didn't need defragmenting.

afaics all that meant was file allocations make a little extra space at the end, so if the file expands it doesn't need to allocate a new block.

If one keeps files around for a long time and constantly adds to them, then the files get fragmented on any filesystem.

The only way to avoid this is pre-allocate all files to their maximum possible size and never exceed that size.