It’s clearly a dark pattern thought up by shitbags because users are more likely to create an account after they’ve typed something out vs. leaving when they find out an account is required to participate.
Even the shitbags over at Mozilla are doing it.
Unfortunately, many people are naive and susceptible to the sunk-cost fallacy; that’s what they are banking on. They know a good portion will just kill the app but the few that bite will be milked for all they are worth.