Good Energy (UK) Customer Service interview questions

There are 3 stages for a job that is 25,500 per annum - a video call from energy specialist, role play, assessment link and a final interview with the energy leader. You have conducted the first interview, there was a role play and other questions, then proceed to send a link to carry out an assessment, then proceed to another one hour interview with another person, why please ? Why is the process long and unnecessary? One would think the assessment would be the first to filter what you are looking for then have a final interview with whomever, the process isnt encouraging.