Open Source has worked fine here. The author doesn't find financial support for the work, so they just want to change winds and that's a perfectly fine path forward.
If this is really much more than a personal project "for fun, on my leisure time", and it became an actually serious product-level project that provides good value in commercial environments for people, there's clearly an opportunity for a for-profit company to step in and cover that niche. But that'd require that users became customers and actually departed from their money to pay for it :)
I guess most will switch instead to asking who's the next project maintainer to work on it, to whom the new bug reports and complaints can continue to be sent for free. But if there's money to be made by using a tool, there should be money paid for using it too. We "just" need to find the new generation of FOSS Financial Sustainability solutions that actually work! Donations don't make the cut.
I wonder whether the author has considered taking the product to a paid level and what would be necessary for it.
Obviously, all contributors have some form of copyright, which may or may not have been waived depending on whether there was an ACL in place and jurisdiction. So he would need to get permission from the copyright holders, maybe in exchange for a percentage of the profit.
Something I learned about being a part of an ecosystem: if you want it, you need to support it and help it stay alive.
That applies to local shops as it does open source projects.