There's a couple of differences. Most notably, Siri isn't 24-hour surveillance. Most of the time, it's an actual command given to Siri. The chance that an unintentional activation contains something sensitive is way lower than a stranger being able to wait for something sensitive. And then, it's accessible to employees of some company, which presumably doesn't make it easy for employees to keep or share these recordings, let alone simply posting a link for everyone to "enjoy". And finally, video is not audio. A few seconds of an audio recording of you having sex cannot do remotely as much harm as a long video of the same act.
But most of all, Apple never promised that Siri was local, never implemented a fake privacy switch that didn't work, nor incompetently failed to protect your data from the entire internet.
What Apple did was bad. They should have been transparent about the manual data processing. And even though other companies certainly do the same, they deserve all the negativity they got, because they're being held to a high standard, as they should given their privacy-focused marketing.
But what Anker did, through either malice or incompetence, should pretty much rule them out for anything other than charges and cables (which are pretty great, TBH).