Work in the US tends to be a long term proposition. You put out huge amounts of documentation showing that you're worth the money you'd earn, your qualifications, your lack of obnoxious traits, and the favor of people who vouch for you. After much weeding, you're extensively interviewed, and if preferred over the thousand or so other candidates, then to work with you. It will last until either you quit or they get mad and fire you, and the expectation is that you will last at least long enough to promote you several times.
Or, there's temporary labor agencies that will lend you an employee for the day. This is good for when your star worker suddenly calls in sick, because a child's playmate sneezed on them or whatever. They'll demand a cut of the worker's daily pay, and certain other favors. After all, the agency did the hard part of sorting the wheat from the chaff, just so you could have someone at a moment's notice.
However, I think there's quite a bit of market for even more temporary kind of stuff. Way more temporary. I need help moving, say. I want 4 hours of labor to haul this impossibly heavy sofa. A temp agency would want me to hire them for the day, which is overkill.
This will also help with the other big employment problem, lack of experience. Too many companies expect their new hires to come with experience, which would be tolerable from one company, but it quickly leads to the unproductive pattern of the ideal employee expected to have burst fully developed from the head of Zeus. Getting the necessary experience becomes impossible, and companies endlessly whine about how hard it is to get good help these days. Everyone leaves angry at everyone else.
So now people can get experience doing one-day-at-a-time jobs, and their contract can be extended if it works out well, or thrown away if it works out poorly. Now what?
I'm invisioning this as a board, where one makes a post, and candidates respond. All sides should allow 24 hours window, which hopefully will make for enough overlap for the two sides to meet.