Technical interviews are high pressure situations that don't just check someone's technical proficiency but rather their ability to cope with pressure, communicate effectively while under that pressure and their willingness / unwillingness to ask for help or recognise their own weaknesses as soon as they realise they can't do something.
All are essential, day-to-day situations any developer will find themselves in. It's difficult to replicate that in anything other than a technical interview.
Having said that, tech employers don't hold the same power they once did. Decent developers with people skills know they can always find work or just make work for themselves if need be. We're entering an era where these guys will set their own hours and pay and the employer will be the interviewee.
All are essential, day-to-day situations any developer will find themselves in. It's difficult to replicate that in anything other than a technical interview.
Having said that, tech employers don't hold the same power they once did. Decent developers with people skills know they can always find work or just make work for themselves if need be. We're entering an era where these guys will set their own hours and pay and the employer will be the interviewee.