The problem with this is all it takes is one bad actor to cause a lot of chaos and destruction. The laws are needed.
Flipper zero’s capability is not based on some super advanced technology, it can be replicated. Banning stuff is an easy way to cover the problem up but instead of actually fixing anything, it is sent out of view of the mainstream and into shallow obscurity.
People who steal cars already break the law, breaking an extra one by possessing the tool is not going to be a deterrent. Researchers and security auditors who stay above board will no longer have access to this tool if they expect to exist in a professional capacity, effectively kneecapping their ability as our allies to help us create more secure systems.