Like I said there are a lot of "helper" apps and browser extensions being used most of which I am not familiar so any one of them could be causing the problem.
Try creating a new user account to see if the issues affect that account as well. Do not use or install any browser extensions or helper items to this new user account during testing. Make sure there are no login items for this new user account (see Users & Groups System Preferences). I would also recommend rebooting the computer and log directly into the new user account for testing.
Try booting into Safe Mode to see if you experience the same freezes (try both user accounts). You may see the screen flicker or flash due to the very basic video driver used in Safe Mode.
These two options should in theory bypass those unknown helper apps. I'm not sure if this will also bypass the browser extensions or not since I'm not sure whether they are per user.
If these options don't help and you've uninstalled those helper apps and browser extensions, then I recommend making sure your data is backed up and perform a clean install of macOS by first erasing the whole physical drive before reinstalling macOS. Test the laptop with a clean install of macOS before you start installing apps & browser extensions or migrating from the backup.
If you still have issues after the clean install, then you have a hardware issue of some sort that will need to be repaired.
If a clean install works, then be very careful about migrating your user account and data since you could migrate the problem back. I would only migrate the user account and the data without any settings or apps.
