So what you’re saying is - if politicians and our media lie to us constantly, we should just give up and open ourselves up to believing any old lies anyone tells us.
If anything, in a post-truth world we should all be trying to hone our capacities of reason, interrogation and logical deduction, equipping us to make our own judgements based on facts and evidence without having to rely on hysteria and hyperbole - rather than abandoning all our faculties and accepting any old crap we read on the internet!