These people are destroying real jobs. You have to see the entire market: where Uber gives a "job"(with no liabilities of a real job), it(by competing on same sector) reduces wages/jobs of other people, driving down average quality of life and median income.
Gig economy only benefits corporations long-term: for them you are just "disposable human resource" not worker paid wages. While you can imagine some bottom-tier income being preferable to no income, its a bargain with the devil, allowing the companies to pay below minimum wage and remove all external expenses - the independent worker has now to absorb them. It creates a norm, where you don't really have a choice between this bottom-tier income and nothing, as real jobs are replaced with gig/contract schemes.
Their claim is they're opening up new markets of their own, e.g. prior to Uber taxis weren't as widely used for bar-hopping or casual trips, prior to Airbnb people would not travel as much as they would look at the hotel prices, decide it was too much, and just not attempt a trip, prior to Taskrabbit someone who bought a new item from Ikea would assemble it themselves instead of finding a rando to do it for them.
Is their assessment incorrect? Are there examples of (a) gig economy company entering a market (b) average income and quality of life driven down and (c) a causal link between the two?
To me it seems like bad economy is the reason those companies came to be in the first place - as soon as sectors like construction or energy or manufacturing start growing and hiring, who's going to consider an offer to drive for UberEats?
It makes products cheaper because it exploits workers more ruthlessly, "who's going to consider an offer to drive for UberEats?" isn't a choice where industry is destroyed and only a UberEats-level job is available(companies which had fair wages(taxi drivers) were driven out of the market).
Service economy differentiates itself on a multitude of dimensions, of which price is just one. By that notion McDonald's should've driven everyone out of business because who's going to buy a $5 or $7 or $10 burger when a $1 cheeseburger is available? Gas station coffee or vending machine coffee should've destroyed all other coffee businesses, as what fool would pay $4.50 for a cup of coffee when a 50c cup is available at the corner 7-11?
The competitive forces at lower segments of the market determine the overall economy. The people who serve you 4.50$ cups of coffee can't afford to drink them.
When your gig-level job can't pay for 4.5$ coffee, you'll switch to lower segment too, and 4.5$ coffee becomes a luxury for a shrinking minority.
The comparison gets moot because you typically don't pick the company who delivers. You just pick whatever's cheapest or selected by default; instead, you pick where you order your food. Because that's the largest factor affecting the quality of the food.
You'll have different segments indeed. Say we keep it simple and you got two: a luxury one and one for the (poor) masses. Most people won't be able to afford the luxury one, so they'll grab the cheap one. (The cheapest one is still either not drinking coffee at all, drink it at a place where its free ie. at work, or bringing your own coffee in a vacuum can.)
Generally (the exception being catering to travellers such as a drive-in near a highway) you won't see a McDs in a rich neighbourhood, and you won't see a luxury restaurant in a poor neighbourhood. Neither the customers nor the workers live nearby.
Also, don't forget people are loyal to brands.
As a final note, I'd be rather interested to see which local brands have disappeared over the years, if that can be attributed to fast food businesses such as McD's.
As for you not buying the view, that is exactly what was being described in the link with first hand experience from a taxi driver in The Netherlands (heavily regulated market by law) which I posted elsewhere [1].
