For physical tasks - you have a locality problem - a person needs to travel to the location where task is performed. Adding transportation costs and time required for it. And they need to have the tools required to perform the job.
One example of this problem being successfully solved is Uber. But the solution is embedded into the nature of the business here.
For white collar type tasks - there are personal assistant services that solve the problem at least partially.
I'm yet to successfully employ one of these, but the general approach seems promising.
For the task of sufficient complexity, it often takes a long time to communicate the requirements in sufficient fidelity
complexity can be inherent, or be caused by you desiring the outcome to be "just so"
Delegation works well when
you have a lot of shared context with someone (minimizing how much information needs to be transmitted)
you've had repeated interactions with the person, which allows them to build a good model of you and interpolate a more compressed set of requirements in a way that you'd find reasonable
prerequisite here is for them to be agentic and not require hand-holding for everything & being capable of forming sufficiently detailed model of you
you need access to a specific skill that would take too long for you to acquire
doctor
lawyer
You'd also resort to it when you just can't perform all the necessary tasks yourself & so it's worth for you to pay the costs of delegation.
There is value in making delegation easier in specific domains and driving down transactions costs as much as possible
How does one minimize the cost of communicating the required task?
Is it valuable to have a set of pre-defined detailed tasks that are easily executable?
furniture assembly is that, TaskRabbit leans into it a bit actually
you can hire people who are specialize in assembling specific pieces of IKEA