Well of course manual sorting is possible, and 80% of the coffee worldwide is still hand-sorted (or so I've read).
But in many cases, these people would also choose a color sorter if one would be available for their size of operations, matching in both capacity and price. This might be a small to medium farm, a coffee cooperative of small farmers, or a small artisanal roastery in coffee-consuming countries. For all of these cases, even your small color sorter is too expensive and has way more capacity than they need. So there is the opportunity that they'd buy a cheaper, smaller machine.
As we found out, a worker can sort 5 kg of green beans per hour under average conditions. So, 200 kg in a 40 hour work week. On the other hand, your small sorter, when running 24/7, can process 250 kg/h * 24 hours/day * 7 days = 42 tons per week, as much as 42,000 kg/week / 200 kg/worker/week = 210 workers. That's way more than most manual sorting operations need. They might have 5 - 30 workers for sorting, could be replaced with a sorter sorting 25 kg per hour, replacing 21 workers.
I'm not proposing to put these workers out of business, but to enable small farms etc. to produce higher quality coffee instead of selling it unsorted to wholesalers. Because then they get a much better price for their coffee as well.
I hope this makes it clear, otherwise I can explain it more. And let me know when your company decides to make a "micro color sorter"