My company does not complain about the small stuff. On the other hand, it only pays for nonrefundable economy flying for everyone, without regard to length of travel (upgrades are on you), and expects people to not pay more than necessary for hotels. Since a lot of those are conference hotels, they are still sometimes fairly expensive. They would not complain about a breakfast or a latte. I believe they consider traveling to be a burden on the employee and are reasonable about expenses. That said, I have had a long practice of not putting in for reimbursement on every little thing. No papers, lattes, metro tickets, fast food or the like. Stuff I might have bought for myself if still home. I want a clean expense report that gets approved with a 4 second look. So mostly airfare (I attach boarding passes and write on them "Upgraded at my own cost"), hotel, some more expensive meals and meals with clients, taxis and ubers, and that is about it.
Also, if the hotel for a conference is expensive, I will sometimes pick another within walking difference if it is as good but substantially cheaper (and I tend to prefer the boutiques over the chains). No one is making me do that, but I am aware there are budgets, and I don't want to be that guy who is known to travel expensively.