the fear is always going to be with people. there is nothing anyone can do about it. and also this fear is not a bad thing actually. at some level it is still even a good thing to have. it keeps you alert. of course as long as it is not irrational.
these are the answers i give to these fears:
1) then learn basic security which is not hard either. and then risk is 1000 times less than losing your credit card.
2) nobody can shut down bitcoin. also since bitcoin is global and many countries have already adopted it fully then one government "banning" bitcoin has no effect. they will just fool themselves.
3) usually businesses plan on staying around and making money so they don't scam. checking their history, how long they have been around,... helps. for example you never say what if Steam didn't give me the game that i bought! or Microsoft didn't give me my windows that i bought!