This isn’t universal, but in your examples, it’s hard because there’s generations of unlearning poor behaviors. I.e., if Mom only dealt with one disposal can (trash) for the last 40 years, and then you put three in front of her, education is pretty important to help undo that behavior.
Also, people are inherently lazy. People don’t prioritize saving energy for example, because it’s cheap and available, it comforts us, and we’ve lived in a wasteful manner for generations. It’s a lot easier to stay in bed than to get up in the middle of the night to adjust the thermostat to a more efficient, and less comfortable temperature. Those are all points of friction.
I’d argue it’s not about designing for jobs people want to get done, but rather for jobs that need to be done. Nobody wants to sort their trash, it’s a hassle! But it needs to be done to meet the needs of the community.
Lastly, we all aspire to be something greater than we are. Sometimes what we know we should do is hard, easy to forget or full of friction, and as such the task isn’t ever completed. But the outcome is a symptom of the problem, not necessarily the desire of the “user.”