To watch movies from a streaming service?

Always, and only use an external device for streaming services, never the software built into the TV.

Apple TV, Android TV or other devices are perfectly capable and better integrate with mobile and other devices in your network.

The tradeoff consumers are sold is trading convenience of in device apps for security.

Smart home devices like TVs, and thermostats should be treated as default hostile and isolated on a guest wireless network instead of your main one.

Use Apple TV for that.