There is a difference.
The leave campaign focused on things that were provably untrue, the £350 million, Turkey joining, the negative impact of immigration etc.
The remain campaign was based on economic predictions, however all predictions are based on a set of circumstances being assumed
Once Cameron failed to declare article 50 on the first day as he said he would, and which the assumptions were based on, then the economic forecasts were suddenly inaccurate. They also didn't forecast the BOE 75bn in QE, which of course is 1% of GDP, and larger than the increase in growth over the next year.
There is a difference.
However, the economic predictions have had some accuracy, inflation went up, and real wages down ( only increasing now because of lower inflation, but the price rises are all ready factored in). Economic growth has been significantly lower than it was before the referendum, during a period of world growth, and investment in the UK overall has fallen, both internal and external.