The traditional 3rd option was the patronage by a rich benefactor. The modern version is patreon. It's imperfect but seems to work pretty well for some.
Patreon is still dependent on the creator caring about what their audience wants, what the market wants, etc. This is a distinctly "populist" approach, which does have its downsides: specifically if there is important work that doesn't have a wide audience, or takes years to get any results.
