Bikes to carry stuff exist and are called bakfiets. You can buy them in the US, they just aren't common, because as long as the infrastructure is so poor practically using one is challenging. NotJustBikes has a video about this.

Bikes are also perfectly fit for towing, though you would probably want an e-bike if you do that regularly. Still, the fed just announced a tax credit for ebikes, so they suddenly just became a lot more practical too.