He was talking for years and educating people why paper wallets shouldn't be used my masses anymore, and this is not his first video about that subject.
It's easy to find all his previous videos and I am sure you will find that he explained several times what you are talking about.
You are right but still it would be a lot better to clarify in this video or use the annotation thingy in youtube to direct to other videos. Some newcomers may not watch every video of his and only see this one and never learn more than this.
To be fair A.A. is not the only case that calls paper wallets "obsolete and unsafe" we have bitcoin wiki (
https://en.bitcoin.it/wiki/Paper_wallet) that is doing the same thing. At least the wiki, it was in 2018 that they finally added the seed phrase line (which still isn't enough IMO).