Well, consider that there are well documented academic studies (that I can't be bothered to look up right now) showing that most hiring processes are no better than throwing darts at a board with regards to retention rate, employee success, and every other measure of success of the HR process. The only thing that is remotely effective are IQ scores, and even then it's only a weak correlation.
So regardless of what the companies want, it's near impossible to accurately judge someone in an interview process. Even if you know what you want, it's very difficult to assess how someone is going to perform in a job through an interview process. The main benefit of interviews IMO is to help managers "buy-in" on hiring decisions.
The work I'm referencing specifically called out Google as an example of an overly-complex practice that didn't result in objectively higher quality candidates. Google's overall quality of engineering talent is high because they are quick to push people out the door if they don't meet the high standards. Regardless, it's very difficult to scale Google's hiring practices, and it's overall seen as a growth limiter for them (even by people internally - it can take 3-6 months to hire one candidate).
So regardless of what the companies want, it's near impossible to accurately judge someone in an interview process. Even if you know what you want, it's very difficult to assess how someone is going to perform in a job through an interview process. The main benefit of interviews IMO is to help managers "buy-in" on hiring decisions.