Uninstall any and all add-ons you have. Delete the add on folder. Trial and error re-install one by one as process of elimination.

Hopefully ZoS suggestions solved it for the OP. Rather than start a new thread for discussion, I'm giving my opinion about the 5 issues in the last post above.

I've experienced 4 of these 5 type of issues whereas I would expect NONE from a AAA game out for 7 years. I was running close to recommended specs. Since upgrading to a PC far far exceeding them (i9 10900KF, Nvidia RtX 3080) a week ago I have experienced only type 1.

1. Hang is usually game or internet
I take this to mean the game world is normal and you can move around but nothing else moves and you can't interact with anything. 5 to 10 seconds later you are kicked to the Login screen. This still happens to me occasionally in Cyrodiil when I transit to a keep that has just flipped. I think this is a game client bug losing the connection to the server.

2. Random kick used to usually be internet but nowdays seems to also be game bugs
I assume this is about kick to game login screen. If due to internet I'd expect the behavior in 1. above.

3. Crash to desktop is almost certainly the game
In our Raid in Cyrodiil this happens to the same people under the same circumstances:
a. Riding across a game world seam
b. Being near certain opposing ball groups
I believe the game client is over-stressing lower-end PCs (and see 5. below). I.e., it is the game.

4. Crash to black screen *without* any ctrl-alt-del recovery on windows is machine/drivers
The game continues - you just can't see it. You can hear the game sounds. The screen is black if you run multiple resolutions and the GPU switched when it failed. Otherwise the screen is normal but frozen. This happened to me all the time when I used LUI Extended Add-On, but it makes no sense that the game can be crashed by an add-on. Something very specific happens to the graphics system - I would think ZOS could figure it out.

5. Hard reboot is drivers/machine
Graphics driver / Overclock too high / Thermal taste degraded / GPU power cable bad. Get latest drivers and try under clocking.

How many types of game bugs are in play here? Game client loses connection to server / Game client causes graphics to try to switch resolutions / Game client fails and exits to game login screen / Game client fails and exits to desktop / Graphics system fails hard and PC reboots? Do these all have different causes?

In what ways can the game client overload the graphics system and cause it to fail? Can this be mitigated? Buying a bigger PC is not a complete answer: I normally have 120 FPS but during siege in Cyrodiil it drops to 35.