I'm sorry, but I don't believe it, and there are errors.
btrfs uses a B-tree, and ext4 uses a hashed B-tree. B-tree being a binary search tree.
Maybe what you mean is that the future of filesystems likes with the B+ tree, like NTFS, JFS, XFS, ReiserFS ...
The primary value of a B+ tree is in storing data for efficient retrieval in a block-oriented storage context—in particular, filesystems. This is primarily because unlike binary search trees, B+ trees have very high fanout (typically on the order of 100 or more), which reduces the number of I/O operations required to find an element in the tree.
Also, if you want a nice comparison of features see:
Note that both JFS and XFS have very high file and volume size limits. Also note that no current storage systems you can buy even come close to ext4 limits.
Also note that btrfs does NOT have a working fsck, unlike all other available Linux filesystems. If you check the benchmarks you will also note that its performance on SSDs is lacking, while JFS and XFS have very good performance: