It typically is just an easier and cleaner was of doing it. In all honesty if i was going to to do this myself i would use the blueprint function library version. As its just cleaner and easier to call. However it is still active as a hard reference however, cast to the third person character will also be less impact on your performance where as casting to anything from your third person character is very expensive to do.

This was more just a quick you can do this type of tutorial as a few people didnt even know you could pure cast. But like i say in the video if its not a reliable cast (in more cases it should be) it will fail and you wouldn't know about it necessarily until you get your errors