Debrid vs usenet and the *arrs?

I currently have a very comfortable lil home server with the arrs and plex (would like jellyfin but it's not there yet for me, currently fielding emby given how Plex is going), basically all sources are usenet.

I'm nearing a point where I either have to delete some stuff or expand space, which is not cheap, and some of my older drives are likely due for some failures too. So after seeing the popularity of debrid I've been wondering if it'd be worth to instead spend the money on it, but would like to ask some questions. I spend maybe around $70/year on the various bits for Usenet and I expect I'd have to spend around an average of $80/year on drives for just expanding storage (obviously assuming I don't just delete stuff). And that's with avoiding 4k just for storage reasons (my internet could take the streaming tho)

Even just the price of Usenet seems to be more than the price of a debrid subscription though and from what I understand I'd not need new disks with it either.

From what I understand debrid is a shared download space for Torrents/direct downloads where if someone adds something it's available for everyone (presumably it gets deleted if noone accessed it for some time and would have to be re-downloaded?). It's possible to mount the content via WebDAV to make it accessible to clients/media servers to stream directly from debrid.

My questions are..

1. Is there still a point to sonarr/radarr with debrid?
2. How is the quality? (both in terms of media quality and in terms of file organisation so things are discoverable and accurate, e.g. chances of things explicitly named wrong so you think you're about to watch Brooklyn 99 and instead get porn)
3. I would likely go the path of using zurg and keeping with Plex/emby - any experience with how well does this work (any recommendations for or against)? What's the mechanism for picking what is available in the mounts to the media server.. or is it just.. everything on debrid?
4. I don't really use any torrents at the moment, from what I understand that's primarily how you get things on debrid. Would I have to start looking for good trackers to get content or is there no need because chances are someone will have downloaded/shared most things?
5. I guess, am I assuming this works very differently to how it actually does? Any experience from people who did the swap from Usenet/arrs to some debrid + media server?

Many questions in a wall of text, I'd be grateful for any answers to any of them! Thanks!