Should i leave Insider Program? What's the point of it?

How are you in the insider program at all without the hub? You signed up got on the insider track and then deleted the hub?

Probiere mal das hier halte auf der xbox eject power und sync. Ca. 10 sekunden gedrück und wartecdaa piepen eins ab nicht loslassen erst nach zweiten piep ton dann bist du im boot menü und guck mal was du auswählen kannst dann einer der punkte dort sollte
dir helfen...

Try this here keep on the xbox eject power and sync. About 10 seconds pressed and wartecdaa beeping one from do not let go first after second beep tone then you are in the boot menu and look what you can choose then one of the points there should help you

Go inside the Insider Hub app on your Xbox. Leave all programs including system updates, and beta tests. You should be fine after that.

That's the thing I can't even get to the home screen on my xbox. I reset my Xbox after trying to do a offline update. And now I have to connect to my hotspot every time and when I do it tells me I need to update. It's a ridiculous cycle I can't get out
of.

"I reset my Xbox after trying to do a offline update"

Insiders cannot use OSU (offline system update) unless you unenroll first.

Unenrolling requires a factory refresh to align with General Availability OS.

Are you able to log into your account on a PC or another console?

XBox Insider program FAQ
has further assistance.

Whether you’re selling or giving your Xbox away, you should remove it from the Update Preview program. If you’ve already sold or gifted it, you can launch the Xbox Insider Hub on another console or a Windows 10 PC and follow
these same directions.

1. Launch the Xbox Insider Hub on your Xbox One or a Windows 10 PC.
   
2. On the main landing page, select Settings.
3. Select Manage devices and choose the one you want to remove from the program.
   
4. Select Done.