Support of authentication methods - OAuth2, TLS Certificate, etc.
In some cases a given streaming service especially over HTTPS can require authentication and perform user authentication process with using of Cookies, JWT or even TLS Client Certificate.
The problem is, that VLC supports only HTTP Basic Authentication in the current versions, but this method is not suitable for using in complex platforms.
In this case, the web browser remains the only viable option, but it doesn't mean the best one in terms of Video rendering.