Admittedly floor beds or low beds aren't for everyone. The elderly would find them uncomfortably low and hard on the knees, but young parents with a toddler will eliminate the fear of the baby rolling off a high bed. As with everything, there are advantages and disadvantages with the style. 
If you are thinking of going that route, here's the pros and cons listed for practicality and style both.

Easy On The Pocket

 Floor beds can be high on style and low on investment

This may seem like a no brainer, but a simple mattress on the floor is cheaper than a formal bed frame! You can choose to do without the bed frame and the headboard or retain the headboard to create the look of a bed without an elevated frame. It'll be easier on the pocket if you've just spent on a new apartment and are being judicious with your finances. That said, floor beds are not a formal look, and may not suit all decor themes.

Kid Friendly

A floor bed with a cute house shaped frame in a kids room

Floor beds are a wonderful option for the kids room to encourage them to roll around and play without sharp corners and hard surfaces to cause injury. If you have a toddler in the house, floor beds eliminate the fear of the baby rolling off the bed from a height as mentioned before. In fact floor beds are recommended as an option to cribs in the Montessori method. Although the low elevation is a plus for kids, it's a major negative for the elderly or disabled as the low height is a strain on already stressed joints like the knees and hips.

The Montessori method recommends floor beds for babies

 Floor beds keep you cooler in the summers

In a tropical climate sleeping closer to the floor is cooler because the area closest to the floor is the coolest in a room as heated air rises. This is a much more subtle application of the basic law of physics that is used to lift hot air balloons! The hot air in your room will naturally rise to be replaced by cooler air, therefore the lower the elevation of your body while you sleep, the cooler the area. A floor bed could help reduce your air conditioning bills in the summer!

Minimalist 

 Low beds create a minimal look

Floor beds fit right in with the new modern-contemporary vibe in the decor world. Depending on your taste, you can choose an angular low slung frame or a mattress on the floor. A minimal look is perfect for a small apartment as an uncluttered space feels larger than an overly decorated ornate option. 

Save Space

 A simple floor mattress bed that can be cleared away to make space

A floor bed is versatile and flexible, if you need the space for a home office or a kids play area all you have to do is roll it away and you have empty room space to do as you please. A floor bed can also be a great option for a spare bedroom as you can turn it into a guest room when you need to while using it everyday as a home office space with the bed rolled up. 

Visual Clarity

 Visually clear sight lines make a room look more spacious

Low slung beds take up less visual space therefore making a room look larger as more space is free or unoccupied. A large bed frame can make a room look overfull and claustrophobic. Resist the temptation to buy a conventional bed for a small room instead opt for a mattress on the floor or for a low bed frame.

Environment Savvy

A floor bed uses less materials, even if you opt for a minimal low slung frame, the materials required to manufacture it will be fewer than a conventional bed frame. Fewer materials equal a smaller carbon footprint! So a floor bed is better for the environment too.

If you decide to ditch your conventional bed, at the least, you'll be choosing something different style-wise, and with the list above you'll be able to make an informed decision.