It annoys me when I upgraded Adobe Acrobat Reader a few days ago. The “All tools” panel keeps showing when I open a new PDF.
I tried some solutions that tell me to open
Edit -> Preferences -> Documents and check
Remember current state of Tools pane, but it does not work on the newest version of Acrobat Reader.
Adobe has admit that the feature cannot be removed. So, the only solution is to go back to an older version. You can just download a previous version of Acrobat Reader, or try:
Click “Go to old UI” in “File”.
Then apply the step above.