I meet a lot of people who wonder how to afford a thru-hike.
I’ve met a lot of hikers.
Some have jobs they can leave and return. Think of nurses who work traveling contracts or construction workers, or wait staff at restaurants or resorts. They save money during the October to March time period. In April to September they hike. Repeat the process, sometimes for a very long time.
Some are retired (me).
Some take a gap year or hike after a job transition (think guys who have left the military or college kids between their bachelor’s and grad school).
Some have wealthy parents (often these are found hiking between high school and college or over summer vacation).
Some go into debt to afford a hike — a mixed choice with a lot of downsides.
But many have an extremely minimalist lifestyle which gives them a great deal of freedom.
Sponsored hikes are incredibly rare. Usually those are available only if you are a famous hiker or you have a parent on the board of the sponsorship company.
The thing is, that except for a small number of hikers who are lucky, it is a matter of hard work, saving, and maintaining a very low cost lifestyle with very few, or very inexpensive, possessions or waiting until you are retired.
That is how people afford a thru-hike.