So, future investors - look at the startups that address the user problems, not the client problems, even though the latter are paying.
Do you think the PMs at Concur just woke up one day and decided to be user hostile because they're asshats? Of course not. They did what the Sales team, and Gartner, told them they needed to give to CFOs so that they would buy it. And then CFOs bought it.
Until someone can quantify the benefit of "better UX" to CFOs, or provide that and all the CFO facing features they want, crappy expense platforms will continue to be the order of the day.
Small quality issues for users would reduce errors, and get expense data reconciled faster. But… by how much? 10%? 20%? No one will care enough to fund a large system replacement for a 10% reduction in expense report filing.
I find it a little hard to see to be honest. Team members might push to use Slack over some other chat solution because they spend all day using that -- I've seen that happen and work. How often do you do expense reports that you're really going to nag the company to buy your favorite solution?