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
Same – happy to seed as needed, but no idea how to find a good, general private tracker for shows and movies
Digitalcore is currently open (.club) scenetime was open aswell recently
They are fine for the beginning. morethentv for tv, nebulance for tv
Private-hd for tv and movies in … hd
Torrent leech for everything scene
Usually having one decent profile (ratio) helps you to get into other trackers