A VPN’s encryption is different than a streaming platform’s encryption. The streamer’s encryption is their form of rights management. So the device/app decompressing the video very much is the point of decryption. If not, the rights management is very broken. If the small edge gateway is somehow decrypting the video stream, you’d have a very rogue device that lots of people would be curious to learn more
Eg a small edge gateway could be doing the VPN, while the end device is decoding the video.