iCloud never fully sync on any device.

iCloud never fully sync (and has never done that) on any of my apple devices. I have an old 2012 MacBook Air that is completely unable to upload any files to iCloud despite being latest update and I have done nothing out of the ordinary. It never has been able to sync fully.

Same goes for my iPad Pro, unable to upload new files and sync.

I got myself a factory reset MacBook Pro (13-inch, 2017, Two Thunderbolt 3 ports) this week that is barely used. I reset everything that is to reset, even re-installed MacOS and reset NvRam or whatever it is called. I updated it to latest and greatest macOS Monterey 12.5 two days ago and it synced fine. After syncing (which happened in the background as I installed apps for work) it seemed to be going great. I bought the 50GB upgrade and moved some files to the desktop. Then it all failed AGAIN. No file uploads, everything is either stuck on "uploading" or pending to upload. I cannot sync with iCloud.

What I have done:

1) Restarted the computer.

2) Powered off the computer for 2 hours and let it charge fully. Turned it on. No change.

3) Logged out, turned of the computer, waited, started it, logged in. No Change.

4) Create a new text document to see if it gets uploaded. Nothing.

5) Signed out of my apple account, restarted, signed in. No change.

6) Disabled everything iCloud related in system preferences. Restarted. Waited. Changed network. Restarted. Enabled everything in iCloud settings, waited 5 hours, changed network, restarted, waited 3 hours. No change. No new files uploaded or downloaded.

7) Executed the command 'touch' on a file to update it as per https://apple.stackhttps://apple.stackexchange.com/questions/313716/icloud-drive-wont-sync-on-mac

No change at all.

8) Followed top post of https://apple.stackexchange.com/quehttps://apple.stackexchange.com/questions/313716/icloud-drive-wont-sync-on-mac

I have unchecked Optimize Mac Storage but to no avail. I have plenty of storage left on iCloud (45GB) and 200GB left on my computer.

9) Removed CloudDocs as per https://apple.stackexchange.com/questions/313716/icloud-drive-wont-sync-on-mac

Now it REALLY will not sync.

10) Done everything above with my MacBook Air. Unchanged situation.

11) Done most of the things above with iPad. Same state.

12) Disabled firewall

13) Checked for updates

14) Changed password on apple account and re-logged on every device

15) Posted this question.

This is my current situatuion:

Stuck at iCloud Drive needs to finish updating before being turned off. Waited 3 hours. Restarted. Waited 3 more hours and now I am here. Same progress on the bar for all these hours.

As the cloud icon indicates, it does not really work.

I have no other firewall, VPN, antivirus, blocker, etc. installed. No modification to hosts file or anything. I have installed two browsers, an IDE, updates, note taking program, KeePassXC and that is about it.

WHY WILL ICLOUD NEVER WORK. WHAT HAVE I NOT TRIED!?

Have anybody have seamless iCloud integration in their OSX systems with larger files (1GB files)? It all started with my backup files that are large, never stopped.

What can I do now?