I understand where you are coming from. Yes, but at the same time these firms don’t mention whether it will held virtually or in person. Also, if push comes to shove and if one is desperate enough and with enough finances of course, they would be prepared to travel to the UK to attend the AC.
Another thing is that a lot of the bigger firms advertise that they can sponsor international students, therefore they should be prepared to accommodate the process while bearing in mind that the candidate might be abroad.
So all of these factors can make up the reasons why international candidates would apply.
Thanks for the clarification.