Same issue with MacBook Air 2020. Big Sur 11.2.3. Fan goes crazy.

This is interesting to know. I dont have any such huge file. With me, its always when viewing PDFs in Preview app.

Yes, this is an absolute shame that this is persistent since months and has not been addressed by Apple yet. Please write here after wiping whether it works or not. If yes, then I will follow the same route.

Thank you for writing. This is frustrating, spending hours and still getting the same problem. I have reported this to Apple support also that this problem is being faced by many users, but whether they are reporting it to the engineers is questionable.

Its still persisting in Big Sur 11.3. CPU usage 150%.

Its been more than a year since this bug is persisting. Is there anyone testing Monterey? I hope its not there in Monterey!