Despite a record of 20 wins in 27 tests, a "gutted" Robertson said he agreed to step down two years into his four-year contract in the "best interests" of the team.
Speculation over Robertson's future had mounted since December amid reports of friction between senior players and All Blacks staff.
However, New Zealand Rugby (NZR) chairman David Kirk denied player power was behind the decision.
“There was definitely no revolt,” Kirk told reporters at NZR's Auckland office.
“The players were very measured and thoughtful in their responses (to the review).
“We’ve spoken to the leadership group before the announcement. Their reaction was -- they just absorbed it. I know this from personal experience: players are players, you get on with it."
Robertson, who replaced Ian Foster after the 2023 World Cup, guided the All Blacks to 10 wins out of 13 tests in the 2025 season but the former Canterbury Crusaders coach came under pressure following a first-ever away defeat to Argentina and a 43-10 loss to South Africa, their biggest-ever test defeat, in Wellington.
The All Blacks were also well-beaten by England at Twickenham in November, ending their hopes of completing a Grand Slam of wins against the Home Nations.
Kirk said the NZR board was unanimous in their decision to replace Robertson amid general disappointment with the team's progress.
"We weren’t seeing the trajectory,” Kirk said.
"We were falling a bit short of the excellence that we’re looking for, it never really got addressed over the year.”
Robertson said he had agreed to quit after reflecting on feedback in the review.
"Coaching the All Blacks has been the honour of my life. I am incredibly proud of what this team has achieved and of the progress we have made," he said in a statement.
"We have brought through a talented group of young players, strengthened the depth across the squad, and set solid foundations for the years ahead.
"My priority has always been the success of the All Blacks and, after discussions with New Zealand Rugby, I believe it is in the best interests of the team for me to step aside ... so a new coaching group has the time it needs to prepare and take the team into the next World Cup."
Kirk said a search for a replacement would commence immediately, with the All Blacks set to play their first Nations Championship tests in July.
Former Japan coach Jamie Joseph is seen as front-runner to replace Robertson, who was unable to replicate his huge success at provincial level with the Crusaders in the test arena.
Kirk confirmed Robertson's staff, including forwards coach Jason Ryan and attack coach Scott Hansen, remained in their roles for the time being but the new head coach would be free to hand-pick his assistants.