The history of dual-pane file managers
fman.io
fman.io
After some time I chose SpeedCommander for Windows and Path Finder for macOS. Both have many advanced features, are easier to use than Explorer/Finder and I do not reget paying for them.
I really hope that fman will catch up to them and have a similar impact as Sublime Text. Having an unified file management experience across my operating systems while expanding it to my needs with plugins sounds like something that I really want. :) But in its current state I feel like it is too early to ask for money. I never saw Sublime Text 1.x or even Sublime Text 0.x but if we compare it to ST, then fman is nowhere near it.
There are many ST users who don't use any plugins and consider it as feature complete. I doubt that this would be the same for the current state of fman.
Users are already happily paying for fman. But you're right that it is still missing many important features. This will get better with time.
I know fman is still pretty young, so for now I'm sticking with FreeCommander. Also, fman was too slow using Windows network drives which I have to use at work. Local files are fine. Plus, there are a few features of FreeCommander that I can't live without including the tab interface, multi-file renamer, built-in archive handling, and many more. Although fman does look like a cool project, hopefully it will catch up in terms of speed and functionality with user-provided plugins.