Upwork keeps rejecting new applications because today it is one of the world’s biggest sites for hiring freelancers. Hundreds of freelance projects are posted every day. Now Upwork probably has an in-house team (or they are outsourcing projects to their offshore team) that is grabbing most of the projects posted by business owners.
When they have an easy way to make more money from their own platform, why would they let other freelancers get a piece of their cake?
The best thing you can do is look for similar sites where your profile will be accepted and you can start bidding for projects.
Hope my answer helps!