The adjustment period is real. I was showering twice a day when I stopped shampooing, because my hair (lots of it, but fine and not coarse) got greasy quick. After a few weeks, it normalized. I can shower once a day now. I still wash it by running my fingers and water through it over and over, so it doesn’t smell. I still have a somewhat dry scalp though, it didn’t really fix that. Don’t really have dandruff, but if I scratch my scalp a bunch or use a comb directly on it several times, I’ll have to rinse the dandruff out.
Debt: The First 5000 Years by David Graeber is a cool book about this whole topic