Why do so many people I know lie about being a caretaker to get money?

I've sometimes made the comparison to being a firefighter, why is it nobody expects them to not be paid for the hours and days they aren't actively responding to a call but they feel free to call out caregivers that are earning a pittance?
And let's not forget that when someone lives with the person they are caring for the caregiving lasts 24/7, it's not an 8 hour day/40 hour work week.

Sometimes someone just does not need more then 1-2 hours of physical care, but requires for supervisorial care which is still actively working. Only so many times you can clean the clean house. Often times the role of a caregiver is reactionary, not like the daily tasks take up that much time.

If you truly feel that your mom is taking advantage of the system and lying about the care that she gives to her aunt then you should report the situation.
This could qualify as fraud, theft and possibly borderline abuse of a vulnerable adult.
(personal opinion here but if you are aware of the situation and allow it to continue you are just as guilty as she is)
Not all caregivers lie about the care that they give and how much they do for the person they are caring for. I had 2 of the best, most honest, loving, caring caregivers the last few months of my Husband life. Some of the ones prior to those 2 were also very good, I can honestly say that there was only 1 that was dishonest and a thief. (I think over the course of 5 years 1 out of 7 is not bad though)

Loveall, You may be underestimating the care your mother is providing for your aunt, who is, after all, living in your mom's home. If your aunt is bedridden your mom is preparing and serving food and providing personal hygiene which is time consuming and a task not all are prepared to do. Not to mention your mom is largely confined to home because she's taking care of a bedridden individual. Care-taking is not "easy money." On the other hand, your mom's suggestion that you lie to receive caretaker money you didn't earn and then give it to her is downright dishonest. Refuse it. There will always be those who will enrich themselves dishonestly, but please Loveall, don't presume that everyone who provides care for compensation is a lie and a cheat. It just isn't so!