My credit card companies have direct access to my bank account because I use bill pay. They can’t automatically withdraw funds if I don’t pay my credit card bill.
in the event of a fraudulent transaction PayPal freezes the money, they don’t take possession of it. They just stop you from using it if it’s in your account. Newer PayPal users have a hold on the ability to withdraw funds while established and high frequency members can withdraw funds immediately. It’s because you’ve built a level of credit trust with them.
If you withdraw the funds and the investigation sides against you (could take a long time) you’ll be responsible for payment. As mentioned before PayPal can take you to collections if you never pay but they won’t go into your bank account and withdraw money independently.
I think most users on this forum follow PayPal guidance (use signature required tracking) and should be covered in the event of a dispute. PayPal makes their money from sellers not buyers so they need to be fair but also don’t want to bite the hand that feeds them if the rules have been followed.