The quality of 3MF and STL files is based on the resolution, or level of tessellation. If you lower the resolution, the 3D model will be less accurate. If you increase the resolution, the model will be more accurate. You can "smoothen" the 3D model's surface and therefore customize the resolution by configuring the deviation and angle tolerances. The smaller the tolerance level, the more accurate the surface’s curves are presented. Together, the deviation and angle tolerance levels alter the quality of your export.
If you intend to use 3D printing at home with your filament-based printer, then you can use low-quality export. But if you intend to build the models with CNC machines or an advanced SLA printer (such as a Form 2 printer), you should use high-quality export. In any case, 3MF is the recommended file format for 3D printing.