According to the Nature Transformation wiki, only five shinobi are known to have mastered all five chakra elements via pure training and without the use of special skills or equipment. This website claims that there are ten persons who can employ all five natural transformations.
So yes, five people can use all five chakras simultaneously.
However, we need to understand that these transformations are parts of a whole, and using one without the others tends to be detrimental to your health. For example, if you use your psychic power without focusing on your mental body for too long, you might suffer from paranoia or even psychosis.
Also, remember that transforming into more than one element at a time uses up part of your chakra pool. So if you want to use all five elements simultaneously, you'll have to recharge your chakras regularly.
A few shinobi can employ eight or four chakra elements, but only the best ninja can come close to mastering all five.
Is it possible for Boruto to employ all five chakra naturals? Boruto is unquestionably a prodigy, yet he is currently unable to use all five chakra natures. He can only utilize three. He may enhance his rasengan with his wind and lightning technique.
Boruto will most likely learn how to use all five elements as he grows more experienced in combat. However, since they are innate abilities, there is no telling what he might be able to do with them if given enough time.
Every character who has the ability to employ more than two chakra natures (and what they are) In Naruto's universe, chakra is the source of all the characters' abilities, yet some may use more than one type at the same time. For example, Gaara is able to create sand clones due to his Sand Style being based on a Mangekyō Sharingan power which allows him to extract kagune energy from his victims' bodies and convert it into chakra.
Even though they are not shown in the series, many characters could also use bone chakra or other elemental chakra. These characters would be able to use both physical attacks as well as techniques that involve an element such as fire, water, wind, or earth. Some characters may even have the ability to switch between different types of chakra during battle.
There are several characters in the series who can use multiple chakra, but cannot use every single one of them due to limitations imposed by the story or their own personalities. For example, Tobi uses nine-tailed fox chakra, but can only transform into a human when using it because of how much damage this would cause otherwise. Also, Sasori uses bone chakra, but he must keep it hidden because it makes others uncomfortable.
Multiple chakra usage is important for characters to have an advantage over their opponents.
Naruto currently possesses all known chakra natures, including wind, fire, earth, lightning, water, Yin, Yang, and the uncommon yin-yang. Shinobi who lack elemental-based kekkei genkai are all born with one primary natural affinity (yes, even senju), which is always the simplest for them to master and employ in comparison to the others. For example, using only wind techniques would be difficult for most since they can't use fire, etc.
However, there are some advantages to possessing multiple chakra energies. For example, a ninja who knows how to use all five elements would be able to create stronger techniques by combining them. Also, if one of a ninja's chakra energies is depleted or destroyed, they will eventually need to recharge it. Recharging one's own chakra requires time away from combat that a desperate ninja might not have available. Hiding or giving your opponent a chance to strike first can also do damage to one's ability to regenerate chakra.
Uzumaki means "spinning top" in Japanese. This name was given to the village because the villagers used to make money by spinning tops. However, due to the fact that these tops were very dangerous and could kill someone with just one blow, the government banned people from making them.
Since this element is responsible for spinners and toys, it makes sense that it would play a role in ninjutsu.