Generally speaking, freelancer websites are all trash - more intent on making a buck for the referral than in actually doing what they are meant for.
The only real exception I know of is Guru.com, except this is from years back.
And even years back, finding someone competent enough for things is hard.
Most people who are competent have no need to use these sites for work…
Particularly in the game industry.
I myself used upwork for a spell. In both roles. Provider and seeker.
They are one of the ones more intent on making money than on backing up their claims about getting stuff done right.
From the seeker side competition is fierce with Indian companies dealing out penny quality work for 2 pennies.
The website takes a large cut of the initial work order, and of anything you make from the same person going forward.
They make it look like they protect you from not getting paid. They don’t.
There’s a lot of scammers on both sides of the medal.
From the provider side: Sure, 2 pennies are cheaper than what other people will bid. But the quality you are given is only worth a penny, if even.
Plus there’s the language barrier for most of them, and it’s often used as an excuse to call something ‘complete’ when it isn’t.
Fortunately, if you create proper documentation you can force people to actually finish work before getting paid. Not that this helps, since forcing people to do something results in work that’s worth maybe a fraction of a penny.
That’s all I got. That and:
Distrust all “freelance” websites and people you find on them (or on here too, there’s known scammers reported on forum posts ) in principle.
Cover your investment with solid contracts and documentation.
Check their skill levels over a phone or even better a screen sharing interview.
It’s usually impossible to know stuff - like when they have no idea of how to use Visual Studio, or whatever program you require - when you are being asked to explain it live by pointing things out with the mouse pointer.
Something as simple as “where can I find the levels pallet” would be able to tell you if they know the engine or not for instance.