Your pain only proves my point. You know it is supposed to be better, regardless of how it looks. There are outliers who neglect the end users, usually because they are too big or well connected to be replaced.
I don't know if it actually does, maybe in theory, we would assume these companies would be incentivized to optimize for speed and experience but you can't use "the exception that proves the rule" when the majority would fall into the exception category. There have been countless diatribes about how in B2B the purchaser is not the user, so speed, user experience, and functionality are all at best second order priorities. The apps I name checked above all probably provide the base level required amount of functionality that covers the needs of a lot of large privately held and all publicly held US companies, they are looking for the corp equivalent of Wal-Mart shoppers not Nordstrom shoppers (this dove tails into penny wise/pound foolish quarterly earning mindset, corporate America is dumb AF.)