Indeed. And I think a good term here is "moral failure", which is exactly what the traditional meaning of "sin" is, i.e., doing something you shouldn't, that you
know, to some degree, that you shouldn't (culpability is determined by the degree to which you understand you are doing something wrong, since understanding is a prerequisite for consent). And small sins are gateways to still greater sins. Indulge them enough, rationalize your indulgence, and you will slowly habituate indulgence and corrupt yourself and shift your moral Overton window. You become what you repeatedly do.
Sinning, in fact, corrupts the intellect and so it quite literally dulls your mind to reality over time. Why? Because in order to choose against what you know is the good decision, you have to turn your mind away from reality, from the truth. Do this often enough and it becomes a habit of blinding the mind to enable doing what you shouldn't. A blinded mind is degraded, worse at grasping reality, and this makes it even easier to commit still greater evil as it has become worse at determining what is objectively good. A downward spiral.
This is why a habit of self-discipline is important. What we call "self-denial" is really the practice of depriving yourself of what you desire that you know you should not desire inappropriately. The obvious example here is food, but it applies generally. Food, as such, is good. However, if I know that I've eaten enough, but an unruly desire for food surfaces, perhaps for food I know is bad for me, denying or repressing that desire is good. One of the purposes of fasting is actually the disciplining of the appetite for food. Consistent practice of self-denial has the effect of regulating the appetite and strengthening the dominion of reason over it, which develops one's integrity. Over time, that unruly desire, ruled over and purified by reasoned discipline, will better conform to the rational order, i.e., what is objectively good. Note how people who indulge their hunger against their own good only become more voracious eaters. They may even become disordered eaters (e.g., bulimia). Rewarding an inordinate (or disordered) desire only reinforces it.
Now consider how vicious, destructive, and irrational our consumerist culture is. It thrives on mindless and degrading indulgence of any and all desires. This is not the way.