IANAL, but, my argument here is that the defendant is proceeding pro se (representing themselves), and utilizing a _tool_ to assist in researching their defense.
Joshua and DoNotPay are _not_ practicing law nor providing a legal service (make sure to have plenty of disclaimers to this effect), but are merely providing a resource and a tool for individuals who are proceeding pro se.
Of course, the failure of the legal system is that being right doesn't guarantee you win, and even if you win, you can wind up bankrupt from the expense of defending yourself.
It is truly sad when violence is used to stifle progress.