The GOP often thinks gov't should be run more like a business. But they have different roles and functions. Gov't is for everybody and often serves those most in need. USPS is designed to cover the entire nation including folks in the far flung hinterlands. It is a service which helps unify the country. And in these days of store closings and online shopping, and people living longer, the postal service plays a key role in people getting their medications, and being able to participate in the economy.
Trump blithely tossed an extra $120B to the military. If we need to pitch in to cover USPS expenses, that's a better investment in the country. Sure you can look into cost-saving measures, and adapting to new conditions, but to start making massive changes in an election year, just a few months before an unusual set of circumstances means that the postal service will be a critical component of voting is reprehensible. Trump has already given the game away that he's defunding USPS in order to limit voting (and cause voting chaos and confusion).