These gig jobs don't promote inequality, they fight inequality.

Without the gig apps, rich people are driving themselves to the store to buy their groceries and poor people are not being paid. With the gig apps, rich people are giving cash to poor people in a mutually beneficial manner.

These apps help find more convenient and mutually beneficial ways that rich people can exchange money for services. If you have an unequal society, you would want to promote as many of these situations as possible. Each one is an opportunity to spread wealth around and reduce inequality.

Getting your own groceries may feel more egalitarian, but it does nothing to help poor people. Hiring them to get your groceries actually puts money in their pocket.