Curious: is there anything fundamentally wrong with subscription services that cost $X a month? It seems that it is a more sustainable business model (rather t

Curious: is there anything fundamentally wrong with subscription services that cost $X a month? It seems that it is a more sustainable business model (rather than relying on advertising and social media) because they're providing a service or product that has actual value to users, enough to have them open their wallets to the companies. Unless there's something I am missing here?