I've posted a few video from our latest trip using this method and it really is easy to do.
The only issue is if you are using a broadband connection uploading the video originally to YouTube can use a huge amount of data. A three minute video from my dashcam is about 450Mb. The size of the file can be reduced if you convert it to mp4 first before uploading it. I've used several apps and currently use one called Youcut Video Editor but there are many alternatives. Some are just converters but an editor is better so you can trim the start and finish if necessary if only to reduce the file size. Youcut also allows you to save the file in a lower definition which saves even more data.