What is your favourite freelancing platform?

So far I’m on Freelancer, Upwork and Fiverr.

I’m curious if I should be focussing my efforts on one in particular if it’s better, or are they all around the same?

I have been with freelancer and Upwork. In my opinion, Upwork is far better than a freelancer. Upwork has a good quality of jobs but in freelancer, you come across many scammers. And if you take a job they will charge you first without the completion.
I had gone through the scam job in freelancer but whatever they didn’t return my money stating that I had to check the client. And Upwork has some free skill tests as well.
So, I would probably suggest Upwork.