As someone who has done pretty significant work with lawyers, especially lately: I think you're drastically underestimating how much lawyers will do up front for free.
My point in this rabbit hole is that doing "free aka spec" work for a lawyer vs designer/developer is completely different. With a lawyer you are talking about possible payouts that can equal to months, or even years of salary. For designers/developers the typical payout for spec work (for freelancers) are more like weeks.
Granted, this whole discussion around lawyers doing spec work vs designers/devs doing it is a bit convoluted. I shouldn't have used lawyer in the example, though I still don't think someone goes into a lawyers office and says "in order to work with me you must complete the following tasks". That's what happens to designers and developers, which I think it BS.