Every good thing has side effects, I believed bitcoin ha play roles of changing lives and improving digital structural economy. But bitcoin also has negative damnation on lives by impoverishing people of their spare resource and income.
In contrary to your claims, the decentralized model of Bitcoin has made it even more secured for people to enjoy trading. When you transact with your Bitcoin, it doesn't have to undergo any central authority to get to the receiver, rather it's delivered peer-to-peer exchange. You literally own and control your own Bitcoin.
3. Privacy- bad people trying to give bitcoin bad name by faking bitcoin apps and site.
Secondly, with the deployment of the cryptographic techniques to protect transactions, Bitcoin is more secured than the fiat currency. As a recipient of a verified transaction, you're provided with private keys which is just like a password (to be simply put) to be able to unlock the Bitcoins. Seed phrases amongst others are more security.
Thirdly, easy accessibility gives Bitcoin edge over the conventional currency. Unless the fiat currency that you have to visit the bank or ATM to either initiate some huge transactions or take some cash. Bitcoin is a digital currency right on your computer and mobile devices with limitless transactions.
And list continues.