I was asked to film myself answering a bunch of related, but otherwise useless questions to test my knowledge. After waiting for a while, I was then asked to remotely connect to a PC and do the tickets. The tickets were very easy to solve, and I solved them as specified under the requested time. I was then told that I needed to have better IT skills, and that my application process was declined. This was a complete waste of time. At no point did I interact with a human. No feedback given. How can I improve if I don't even know what I did wrong?

It is a waste of time. First, you need to answer a million stupid questions. Next, you need to do an IT test. After that, they request that you film 3 videos explaining DHCP to non-technical people, about your professional experience and which workstation configuration would recommend for basic video editing and VPN client. After all that effort, you would expect that company to at least call you but no. Waste of time. AVOID!