It's much more obvious that someone is holding up their phone to record than someone wearing glasses containing an inconspicuous camera and recording LED that may have been tampered with.
Sometimes it is. I regularly see people scrolling TikTok and Instagram in public, they might as well be shooting ultrawide 4k footage and I'd have no idea.
... and streaming it live to Instagram or YouTube
Tampering is much harder than using an ordinary phone in a way that looks inconspicuous.