.ch is nothing more than a ccTLD, which represents the country of Switzerland. From my knowledge and research, there is nothing inherently special about .ch, or any domain extension for that matter when it comes to streaming.
There is, however, a domain extension which is marketed for streaming music and/or video. That extension is none other than: ".stream". Here is what Godaddy has to say about (dot)stream.
Look it, at the end of the day, domains are domains. Use .ch if you are intending to target users of Switzerland, as that is the purpose of this ccTLD.
If you want to buy a .stream domain name - there is nothing special about it other than the extension which implies your intent to "stream".. if you will.