There is simply no way that cost cutting won't reveal itself in certain ways, many of which will appear as "slippage" in the magic. Disney, (like all companies), has engaged in cost cutting and staffing reductions. Now, if a company were to do that and maintain 100% of its previous level of service, that would be magical indeed! Alas, this is the real world.
Emblematic of all of this are the comments on towel animals. The OP states that they did not receive any, and that this is a noticeable difference (in the negative column). Others chime in and say that towel animals have been gone for a while now, as if this is somehow supposed to negate the OP's sense of a noticed decline in details. But doesn't that simply prove the OP's point? Towel animals used to be "common magic", and now they are gone. It really doesn't matter when they disappeared, does it? And it doesn't really matter that the change is "across all Disney properties". The OP's point is that they used to get them, and now they don't. Indeed, the fact that this is a change across all Disney properties goes to prove that this was an intentional cutback. The Mousekeepers didn't unilaterally, and simultaneously decide on their own to stop making them. They had to have been told to stop making them. Why? Perhaps Mousekeepers spend two fewer minutes in each room that they service, and thus can attend to more rooms in a day, and hence, Disney can cut back its staffing. So when someone notices things like towel animals missing, or trash cans full, or bathrooms that are not as tidy as before, you can chalk it up to cause and effect. The cause is cost cutting and the effect is a perceived decline in details. Disney is gambling that most people won't notice or won't care. But when a Dis'er who has been going for many years does notice, we should be neither surprised nor critical of their post.