finder not launching in big sur

There is something fishy in your system installation.

Try this: restart in Safe Mode. This is slow to boot and work, but is a relevant procedure for cleaning caches and stuff, and as a test.

Does Finder work in Safe Mode? (I expect the answer to be "yes").

Download and run Etrecheck and post its full report here, so we can look for possible causes of the problem.

Use the "additional text" button below and paste the report into the text box, as it is too long to paste directly in the message.

There must be some big issues caused by something that runs in your account when you start up normally.

Try this: start in Safe Mode, and then post here the contents of the following folders:

/Library/Extensions

/Library/LaunchDaemons

/Library/LaunchAgents

~/Library/LaunchAgents

Note: to reach each of the above folders, in the Finder press Command-Shift-G and then paste the corresponding line above and click Go. For example:

It launches automatically when the device is powered up.

If you don't have the Finder running, what happens if you click the Finder icon in the Dock?