In most settings, printer resolution is more a matter of preference than need. Direct thermal printers are available in three default resolutions—203, 300 and 600 dpi. Both e-commerce and online postage sites can work with 203-dpi models without any problems.
Some will claim that platforms like Amazon FBA require at least a 300-dpi printer, but such claims are disputable. Check out YouTube. Many retailers post videos wherein they use a 203-dpi Zebra or Rollo unit on the Amazon FBA page.
Higher-resolution printers are not only unnecessary in most businesses, but they are also more expensive and tend to be slower. Other than preference, their use is justified in only a few settings. Healthcare and chemical lab vials smaller than your pinky finger are some examples. Their barcodes are so small that they need to have better definition than usual.
Some may argue that printing complex logos requires a high-resolution direct thermal printer. However, image-enhanced and colored logos are better off created using an inkjet, laser or thermal transfer printer. Remember that logos promote branding. They need to be printed richly to be eye-catching.
Check your settings if you're unsatisfied with how your 203-dpi gadget performs. It may just be printing on grayscale, using a light default shade, etc.