There are a few beneficial reasons for using a box spring bed base, such as:

They add height. A box spring is a way to provide a free-standing platform to your bed without needing to purchase a metal bed frame. Whether you choose a low- or high-profile box spring, raising your bed off the ground can create easier access, reducing the risk of potential injury over time. A box spring gives your mattress a flat, even surface to rest upon, which can be beneficial for your spine, positively affecting your sleep quality.

They provide extra support. Sleeping or other movements can cause wear or degradation to your mattress over time. However, a quality box spring can absorb shock and help protect your mattress while also helping keep your mattress’s center from sagging, increasing its durability.

They aid in ventilation. Air circulation is necessary to keep your mattress fresh and mildew-free. With a box spring, you increase the breathability of your mattress, preventing the build-up of dust mites or other harmful allergens that can affect the quality of your sleep.

The type of box spring you choose depends on the kind of bed you have and the features you prefer. Here are a few factors to consider when choosing a box spring:

Height: A high-profile box spring is better for those who need a little extra height when getting out of bed. If you have a deep mattress (or are shorter in height), a low-profile box spring as your mattress foundation may be a better option.

Size: Choosing the right box spring depends on the size of your mattress. The box spring must be appropriate for your mattress size, without hanging over the edges. Additionally, if you have a queen-size bed or larger, you may want to consider a split box spring, which comes in two pieces to make it easier to transport through smaller or narrower spaces.

Type: Certain mattress types are better suited for box springs than others. For instance, innerspring mattresses or two-sided mattresses receive the best support from box springs, while memory foam mattresses are softer and need much more support than a box spring can provide.

Style: If you want a headboard to accompany your mattress, then first you have to make sure that the box spring has the proper reinforcements to support it. In addition, if you’ve purchased a platform bed, you may not need a box spring unless you want additional height or it’s a requirement to fulfill your warranty terms.

Source from:https://www.masterclass.com/articles/box-spring-benefits#what-is-a-box-spring