Slow streaming speeds are dependant on the streaming service and the platform that this is on.
These services do work better while using a LAN (cable) connection.
If you are using a streaming service other than Netflix or Showmax, like Kodi, you must remember that the backbone of this service runs off Peer-to-Peer (P2P) traffic - also known as torrents. Torrents work by other users sharing files for you to copy and in this case stream. If there aren’t enough users sharing the content, the content can be slow to stream or download (or may stop entirely). No amount of bandwidth will fix this.
It may also be illegal. Rule of thumb: If you aren’t paying for the streaming service we cannot guarantee your speeds for this.