I moved away from Opera some month(s) ago because of performance issues with zero tabs and zero extensions active.
But what I noticed is that Opera hangs on history. I now had the time to do more investigation and for me the 105% CPU browser usage @Shift-Esc disappears when I rename my history file
@ C:\Users[Windows username]\AppData\Roaming\Opera Software\Opera Stable
I renamed the file "History" to "History" and my zero tab CPU 105% usage disappeared instantly. The only problem is that your history is gone as well ^^.
Might give Opera another try. Because Brave browser is also not the perfect alternative.