I don’t necessarily agree with the panel interview point. On a general level, sure, it’s dated. But there are plenty of legitimate and obscure reasons to do it.
Companies that don’t record interviews generally require a first hand second opinion, whether by an active interviewer or just an observer.
Also, in recent years I’ve always been interviewed by a panel where different people have different specialties. A developer in language x, a developer in language y, an ops engineer, an architect, etc.
It’s true that when you do interview you generally interview for an advertised role, but it happens a lot (speaking from experience on the other side of the table) that someone glances at your resume and says “hey, let’s also asses experience in area x or z as we have a potential need”.