People that want to fill their car with goods in one trip will continue to do so, but it won’t be in the city centre.
Perhaps all along they shouldn’t have, but it was possible/practical before.
Now they will go to the city outskirts to buy larger/bulkier/more good. The sellers thereof will suffer and/or be replaced by car-free friendly businesses (restaurants, cafes, light-weight goods).
That’s all fine long-term, but I’m shedding tears for the businesses that did exist and may not when the environment suddenly changes around them.
Not only those, the fans of bicycles and public transport also suffer when they have limited options for shopping at particular places that are only present in the outskirts. In Vienna, IKEA is now opening a store near this "Mariahilfer Straße" at Westbahnhof, where there's also a huge public garage and a huge shopping centre was built a few years ago - you could say that real shopping is moving where the cars can still go in the city centre, while the former shopping street is slowly turning into a tourist promenade with bars, clothes and souvenir stores.
In reality there are much more nuanced solutions. E.g. if you have a small street with people living in it and the majority of the streets traffic comes from cars taking a shortcut between two main roads, maybe closing that direct connection and creating a dead end is the better solution that boosts the atractivity of the whole street, while at the same time making it more friendly to pedestrians, locals, cyclists etc. Cars can still enter. They just have no reason to do so, except if they live there.
The only downside is the loss of a shortcut, which might have impacted traffic on the main roads negatively.
In traffic there are often situations were all involved sides win if you take something away or encourage certain uses while discouraging others. On other paradox occasions, everybody can lose, if you add more lanes to a street.
In case of Mariahilfer it might be still possible to deliver, but the attractivity as a pure transit street got reduced, simply by showing what the priority is. If this impacts other transit routes also in a positive way, I don’t see why Vienna should do more of this thing — especially if it is willing to win the title of “City most worth living in” also in the future.