Low-frame bikes that are easy to mount — great for all ages and cargo loads.
A step-through e-bike drops the top tube so you can get on and off without swinging a leg over the saddle. That sounds like a small thing until you are stopped at a light with a loaded rear rack, wearing work clothes, or dealing with a hip, knee or balance issue. It is also the practical choice for cargo loads and child seats, because you can mount the bike without kicking the cargo. Step-throughs were once marketed as women's bikes; today they are simply the most accessible frame shape for anyone.
The engineering tradeoff is frame stiffness. Without a top tube triangulating the frame, designers use a thicker, often curved down tube, which adds weight and can still allow a little flex under hard pedaling or with heavy cargo. Good step-through frames manage this well; cheap ones can feel wobbly at speed with a loaded rack. Sizing is also less granular — many step-throughs come in one or two sizes with an adjustable stem and long seatpost doing the fitting, so check the manufacturer's height range rather than assuming it fits.
Beyond the frame shape, step-through e-bikes span commuters, cruisers, fat-tire bikes and even cargo bikes, so use the frame as a starting filter and then judge the bike on its own merits: brakes, battery size, whether fenders, rack and lights are included, and the sensor type. A torque sensor and hydraulic brakes elevate a step-through from convenient to genuinely pleasant. Owners whose step-through has started cutting out on bumps (often a connector issue around the down tube battery) should stop and get an E-Bike Assessment rather than ride with intermittent power.