Beach cruisers are not necessarily the "best" bikes, as the best bike depends on a person's specific needs and preferences. However, beach cruisers are popular for several reasons:

1. Comfort: Beach cruisers are designed with comfort in mind, with wide, plush seats and upright handlebars that allow riders to sit in a relaxed position. This makes them ideal for leisurely rides on flat terrain.

2. Style: Beach cruisers have a classic, retro look that appeals to many people, and they come in a wide range of colors and designs.

3. Simplicity: Beach cruisers are often single-speed or have a few gears, making them easy to maintain and less likely to break down. This also gives them a simple, minimalist look that many people find appealing.

4. Versatility: While beach cruisers are most commonly used for leisurely rides, they can also be used for a variety of other activities, such as shopping or running errands.

In summary, beach cruisers are a great choice for people who prioritize comfort, style, simplicity, and versatility in a bike. However, for more demanding riding, such as off-road or hilly terrain, a different type of bike may be a better choice.