On the other hand you can at least expect that if someone causes an accident they will suffer consequences. Courts and insurance exist as mechanisms to transfer liability including for medical bills, and the criminal system (in many countries) can and does punish people for reckless driving.
Sure, you still need to look after yourself in the moment - but there are incentives in place to discourage drivers from misbehaving and those incentives do help reduce the likelihood that you will be a victim of an accident. They’re not great! Bad drivers get away with a lot, and cyclists are not adequately considered in many mechanisms, but they are better than nothing.
Yet ‘nothing’ is what we have with respect to online fraud, where the situation is more akin to one where driving laws don’t exist or aren’t enforced, nobody drives cars with license plates, you can’t get insurance, and if you are run off the road the police’s reaction is to tell you that roads are inherently dangerous places. Bad drivers will never be caught, and if they drive over you they get to steal your bike and sell it. Entire businesses are set up around forcing cyclists into streets where they can be mowed down with steamrollers, and the police claim to be powerless to stop them.
There are numerous mechanisms that exist that make it possible for us to share roads without inherent trust. And even those are inadequate. Fraudulent behavior online has none of the societal mechanisms that we have created to constrain driving.