Hauling By Bike

Cargo bikes come in many forms. The first one is called the 'Long Tail.' These bikes are built for carrying large loads behind the rider and it takes some experience to make sure the load is balanced on each side. Several companies make cargo bikes with and without electric-assist.
Madi Carlson is a Portland mom who uses her long-tail bike to great effect transporting her kids, groceries, and donations.

As the name implies, these machines are designed to work hard and do what regular bikes can't. The company Workcycles sells a bike which is the same length as a standard frame but is built strong enough for heavy loads like a full size rug. The advantage of having a strong front rack that doesn't move with the wheel is that the weight is more stable and doesn't shift when the bike is turned.

Also called 'Bakfiets' from their origin in the Netherlands, these front-loader bikes are often preferred by parents for making it easier to talk with children. They also have the advantage of keeping the weight low and centered which reduces the chance of being off-balance.
'Momma Moose' is a London resident who uses her cargo bike for regular hauling and for ferrying kids.

You don't necessarily need an expensive cargo bike to transport big loads. There are plenty of people who have carried impressive weight with just the innovation of using what's available. Whether someone is doing hard work or taking a vacation, a well designed bicycle setup can carry 50kg (100lb) distributed on the front and rear carrying racks.
Years ago I rode a bike like this across North America and I'll sometimes use the same bike for a trip to the wilderness.

My own preferred option is a bike pulling a trailer because it allows for very large loads with two side-by-side wheels to keep everything stable. A properly built trailer can deliver items as heavy as 150-250kg (300-500 pounds).
Aaron has hauled various loads by bike trailer including plywood, trees, furniture, and this rototiller.

Bike trailers can even be set up in tandem to carry truck-sized loads around town. This fellow in Strasbourg uses a heavy-duty cargo bike and trailer combination.

For very large loads or frequent deliveries, nothing beats a custom cargo truck. These are mainly three-wheel hybrid human/electric powered and small enough to fit into less space then a gas powered van. Many of them can deliver loads of more then 500kg (1000lb) with ease.

Not everyone feels confident hauling large loads with just human power. Some people live in hilly areas or have longer distances. That's fine. Battery technology has grown dramatically and e-bikes are transforming regular bike riders into super-haulers. With 1/100th the power, an e-bike can carry the same loads as most people haul in an electric car.
Courtney has used her e-bike for both regular grocery runs and larger things like furniture.