Personally I use public trackers the most and only recently private trackers for stuff in my native language.

I did setup i2p a few days ago and currently have only downloaded around ~1GB. Most of my bandwith (143 GB in / 135.5 GB out) has come from just having it in the background 24/7.

The advantages of usenet don't really apply to me (longer retention, faster speeds, no vpn)

Streaming i find useful for checking if something is worth downloading