I think this type of logo was commonly used in the 90ies early 2000, but with slight variations. My scool's logo (in the EU) looked similar. that's why it seems so familiar to most of us.
Yeah, for the 100 bucks they take each year, just to be able to publish apps on their platform, there's really no financial excuse for not making it better.
Why would there need to be a signature to every post? According to your statement, any service that provides OAuth/JWT would be prone to this fatal flaw, wouldn't it?
Sure, the algo suggested some of these videos multiple times, before I even watched one of them fully.