This is a 12-roller robot 3D-printed DIY omni-wheel - a part of Kiddo companion robot. This open-source design incudes 3MF, STL, STEP and SolidWorks files.
If you 3D-print PLA only, I don’t think you need a dryer. But if you print just about anything else - PETG, ABS, ASA, Nylon, TPU, polycarbonate and so on...
If you print only PLA filament, I don’t think you need any of this “nonsense”. Otherwise, if you print just about everything else including PETG, ABS, ASA, Nylon, TPU, polycarbonate...