Worst case you'll have to do an interview (nothing too crazy, outside of FAANGs). A couple of hours of your time is cheaper than paying X% of a year long contract.

You're paying a lot for what's essentially a reputation manager. I just have a nice website for my software consultancy: past clients, team page, how we work, a few blog articles, etc.

I don't think people go to my website and think "Oh, this testimonial is not a review approved by Upwork.com, it's probably fake and these guys didn't even work for these companies".

I used to be pretty big on freelancer.com when I was still working solo and I stopped using it when I started having a few business contacts I could leverage repeatedly (including some that started as freelancer.com). Finding a job, as a software consultant has never been particularly hard.