Definitely do not agree, this doesn’t make any sense, how can a software wallet installed on a phone that has access to the internet (to sign you will need it to be online) be better than an air-gapped signing device, it can’t be. With the setup in the video not only you have more attack surface, but you also have a much larger possibility of screwing up when someone actually needs to move the funds. 

 A suggestion open to discussion.
If you see the whole video your phone is off. 

 Yes I noticed that, but eventually you will have to bring it online to sign the transaction, which is not a great option since you can sign on an air-gapped device and avoid it ever going online.