Don't underestimate the value in a multitude of skills. When Argentina's economy collapsed in 2001, I'd prefer to know how to write code, do laundry, and wash toilets than only knowing how to write code.
I went to university with a girl who didn't know how to operate a dishwasher. At first, I assumed it was because her family had not been wealthy enough to own a dishwasher; later, I found out it was because they were so wealthy they had servants who loaded and ran their dishwasher for them.
The problem I have with people who say things like this is that these things are easily Googlable. I didn't "know" how to do laundry until I went to college (my sister and I had specific chores and laundry was one of hers). During a fight with my sister when I was still in high school, I recall her using that as an insult: "You don't even know how to do LAUNDRY".
I needed to do laundry my first week of school: I couldn't (and to this day can't) even fathom what the phrase "know how to do laundry" meant. Separate whites and colors (or don't), put the clothes in the machine, and press the button.......what kind of mental deficiency is required for someone to think there's an actual gap between "knowing how to do laundry" and "not knowing how".
Loading a dishwasher and cleaning a toilet would seem to be similar. The only gap between "knowing" and "not knowing" is perhaps three seconds of Googling (in case there's some pitfall about what you can and can't put in there).
Presumably the people delivering groceries or doing someone elses laundry weren't making $50/hour in the same profession at some earlier point in their career.
But these jobs just didn't exist(unless you count full time maids for example), so it doesn't make sense to talk about job security or whether they were contractors or not.
I'm not sure we have enough data yet to say whether the people doing these jobs previously did or didn't have better paying or more secure jobs. Anecdotally, there are many people whose income and job security have severely declined, and who been relegated to low payed variable-workforce service jobs. I don't know to what extent people like that are represented among the taskrabbit-type service workers.