That experience was absolutely demoralizing in terms of what she was able to actually make. Granted we live in a lower density city in the southeast so that result makes sense. But everything is very skewed toward the company in the case of Instacart...mileage reimbursement is from the store to the delivery...and you can be sent 10-15 miles from your point of origin to the store to purchase goods at.
I'm not surprised at all that Uber (and the gig economy as a whole) are squeezing their "independent contractor labor force" given that for them it's just a stepping stone toward a fully autonomous pipeline. The calculus here isn't toward establishing and maintaining a happy and committed workforce but bridging the gap between funding and profitability through autonomous solutions.
I don't know what the answer is but I couldn't imagine being in a position where one of the few viable options available for any sort of gainful employment was working as part of the "gig" economy.
edit: If that rate is intended to also cover fuel costs then fuel can easily eat up >10% of that $0.60/mi rate. Man.