Is it worth it for me to build a server?

I was told about the streaming benefits of a NAS server how it could basically remove the need for streaming services. I’d like to do that but I don’t have an accessible amount of data that I need stored, the media would be it. So would it be worth it for me to even build one. I have a bunch of old pc parts that I assume would be perfect, I would just need to buy the storage.

Are there other uses I could use the server for that could be beneficial like internet or something like that?