That's not "theft," per se, but rather a video created with Invideo. It's an AI service that creates videos from bullet points you provide.
Through an agreement with stock agencies, it pulls assets from various sources, like Storyblocks and iStock to create videos. The free version has no option to remove the watermark. Paid versions create higher-resolution videos without watermarks.
I'm told stock clips used with this service still count as downloads for stock contributors, so participants are compensated at some level for usage.