They had no vendor lock-in effect like Apple, Microsoft or Google and no social media network efect like Snapchat, Discord, Meta that would guarantee their customer base to stay long term on the platform. They also couldn't monetize their users' personal data through ads as much as the other chat apps and social networks. And it was only a matter of time before juggernauts with valuable IPs like Disney, Warner, etc. would build their own streaming services to disrupt them.
The moment their competitors with the desirable IP would jump in the ring, or their content was no longer addictive, or their customer base would feel economic hardship, or their VC money dried up, their service could be easily disposed of without a hit to quality of life to their users.
Also, people could pirate their content basically for free, so there's also that, versus the likes of Disney, Warner, etc had other revenue streams besides just a streaming service.