I've got the same problem, and I'll run you through my process.
I have repaired the game files and EAC itself repeatedly.
I have uninstalled everything related to EAC, Origin, Apex, or EA in general, twice.
My two separate uninstalls were installing fresh to my external harddrive, which did not fix the problem, and then uninstall-reinstall again fresh to my main drive (where it is currently.)
I'm unable to delete the easyanticheat.sys file because it says "File is currently in use by another process". Origin does NOT launch automatically on startup.
I did formerly have Valorant and Vanguard, but uninstalled both because I was aware of the Vanguard-EAC conflict potential. Made no difference.
Uninstalled and reinstalled my GPU Drivers, made sure everything was up to date, did not improve.
Restarting my computer fresh allows me to launch the game 1 time. If I close it, it will give the 30005 CreateFile failed error 100% of the time until my next restart.
This problem was first observed immediately following the Chaos Theory update on March 9th, and has not been resolved since then.
I've tried everything at this point except installing it on steam and seeing if it's playable that way, but judging by other people's responses, I doubt it would make a difference. The game runs perfectly fine on the one launch I can get per restart, but this has very much put a damper on my desire to play, as I'm sure it has impacted others.
Win10 Home version 20H2