Hi @F1Z1K. Thanks for taking the time to give the Arduino IDE 2.0.0 release candidate a try and for your report.
Others have reported the same problem. There is some discussion about it here: CPU utilization Very High
This issue is being tracked by the Arduino IDE developers here:
If you have a GitHub account, you can subscribe to that issue to get notifications of any new developments related to this subject.
I am unlucky in my fortune to not be one of the ones who are affected by this so I have not been able to effectively investigate it. The same goes for the Arduino IDE developers. So any specific clues from the community that might lead us to being able to reliably reproduce the issue might be very helpful in finding the solution.