You make it sound like the solution is obvious. It isn't. There are a lot of discussions that try to solve this problem, for FOSS as well as for other fields. Patreon, Gratipay, Crowd Supply and Kickstarter are just a few options that have tried to solve this problem with mixed success. There are many projects that are wildly popular or used in critical infrastructure around the internet that are chronically underfunded.
My opinion is that extracting funds from people online is a high friction event. When combined with FOSS projects that might be used by a large user base but where each individual derives benefit smaller than the friction of a funding payment, the project, or individual maintainer, has trouble with remuneration.
> "I am an exceptional coder with an unfortunate tendency to only consider the complexity of a problem or the elegance of a solution when considering the value of my work."
A pretty bad faith reading. Maintaining a successful (GitHub) project means dealing with community feedback, triaging and fixing bugs, writing documentation, popularizing/marketing and managing code contributions, at the very least.