I started with Upwork a number of years ago and found success and regular work. It was actually a large piece of where I found work as a voice artist. But then they changed their fee structure and I no longer try to find new work through the site.
We must now pay for audition credits AND they then take a percentage of the contracted fee.
I felt this was a money grabbing attempt and it made me decide to leave the platform except to keep my past clients who still work through this site.
Otherwise I have left and will spend my time elsewhere.
It is a good platform and one that I had success using. The value was once good. But not it is not a value for me any longer.
If you are just starting out it can still be a great platform for you to use. If you have been in the business a while I say skip it.