Why ext4 File System is better than NTFS?

ext4 is better, because it is not built by MS, of course. ;-)

• How are searches being handled?
• How is the allowance of access to a file being handled?
• How does the FS do deletes (i.e. remove a file)?
• How does the FS do inserts (i.e. create a file)?
• Does the filesystem need to be defragmented?
• How is caching being handled for that filesystem?
• What are the FS-features (e.g. compression)?
• How does the FS recover from crashes (journalling, ...)?

Keep in mind that NTFS is evolving as well.

The question which one is better depends on the use-case. There are points, where NTFS is "better" and there are points where EXT4 is "better". It depends on the specific needs which is more important.

"Better" is subjective and not very meaningful. Nevertheless, you can get a good comparison of filesystems (including NTFS and ext4) on Wikipedia. There's also an article on PC World that covers it more briefly.

Ultimately you should remember that performance metrics in this case are not really a good measure of filesystem performance, there are too many variables involved, especially in that the performance of a filesystem is very related to the performance of the driver being used to access it.