Looking for a service for outsourcing small tasks...

I'm looking for some kind of service where I can add tasks into a list, and each task has a description of what needs to get done, and then there's a network of virtual assistants who can pick up the tasks as jobs if they can do it.

For example

• desk research (this is the main one I'm looking for. For example "research XYZ and compile all the findings into a Google Presentations")
• email outreach ("email all the people who I add to this list and send them this email template, if they respond then let me know")
• basic sales calls
• preparing slides
• basic copywriting editing
• transcribing audio to text

I know about sites such as Fiverr and UpWork, and those platforms are get for outsourcing small jobs to people. However, the setup process is a massive overhead. On UpWork you have to "interview" people, and make sure you have the right "candidate". I get the sense people on those sites are looking for employment, rather than a gig-economy style jobs.

Where as what I'm imagining is more like a to-do list of tasks with small fixed-fee costs, which people pick up and deliver within 24-48 hours. Kind of like the Uber of small tasks for virtual assistants.

Maybe something like this doesn't exist, but if anyone knows of a service which sounds similar, or even a way of using UpWork and Fiverr to achieve this, then please let me know!