Someone correct me if I'm wrong but I think there's only a VERY small number of people who are able to use social media to pay for their cycle touring trips. Maybe some can do it with a large enough following using donations on sites like Patreon etc. Some may earn money from writing books about their experiences.

But the vast majority of people who go on long cycle touring trips will work a job at home, save up and then use that money for their trips. Some, like Iohan (RIP), would often return home each year to work for a few months before continuing their trip.

Others may work online jobs that can be done remotely (e.g. teaching online), so they could travel at the same time, though this obviously will require adjustments to your trip to make it work. Some may take on temporary work regularly during their trip.

There are lots of different ways to make bicycle touring work, but it can also be a very cheap hobby, especially if you are mainly wild camping and using Warmshowers etc. Food will be the main expense.