For everyday utility riding around town, I prefer a bike that can carry a pair of grocery bags in back and at least one up front. This allows me to carry a week’s worth of groceries on one bike if necessary (this is assuming a “normal” sized bike, not a cargo bike). A bike set-up for hauling this type of load will typically have a full-sized touring rack in the rear and some sort of basket or porteur rack up front. Alternatively, it could have a “lowrider” touring rack up front and a second set of smaller panniers. Besides providing extra capacity, having the ability to carry weight on the front of the bike balances the load between the front and rear, improving stability on most bikes.
People talk about the need for low trail geometry for carrying loads on the front fork, and perhaps for touring or randonneurring that’s true, but I haven’t found it necessary for utility riding. More important is a good center stand that holds the bike upright and steady when loading. A centering spring or strap to hold the wheel straight during loading is a good idea as well. When we’re talking about short trips to the grocery store, ease of loading and overall carrying capacity are more important than light steering for long days in the saddle.
If you’ve considered a porteur/front cargo rack for your grocery getter, but you’ve hesitated because your bike’s geometry isn’t optimized for carrying a front load, I’d encourage you to give it a try; personally I feel it’s a non-issue for the typically short distances most people travel for grocery shopping and errands. More important is a set-up that’s optimized for the loading process; once the bike is loaded and rolling, you’ll quickly adapt to the steering and you’ll be glad for the extra carrying capacity.