Rank in SERP is exactly same as other domains like .com, .net and etc. Reason most of startups to use .io domains is because there you have a space to found cool one-two word domain.
Short and memorable: .IO domains tend to be shorter than traditional domain extensions like .com or .net. Shorter domains are generally easier to remember and can be more brandable, which can indirectly contribute to increased traffic or user engagement. Tech association: The .IO domain extension is derived from the British Indian Ocean Territory, but it has also been adopted as a popular choice among technology companies. This association with the tech industry can give the impression of being cutting-edge or innovative, which may positively influence perception or user trust. Availability: Compared to traditional domain extensions, .IO domains still offer a wider range of available names. Many popular .com domains have already been registered, making it difficult to find a suitable and memorable name. The availability of unique and creative names in the .IO space might make it more appealing to some businesses.
In my experience, .io domains have gained popularity for several reasons.. .io domains can be seen as a bit more unique and memorable compared to traditional .com domains or weird extensions like .xyz or .money, making them stand out in the digital landscape. However, it's important to note that domain extension alone doesn't guarantee better rankings or trust scores. Search engine optimization and trustworthiness depend on various factors, including content quality, user experience, backlinks, and more.
The io domain name is shorter, making it easier to remember. This domain suffix is closely associated with technology and has a low registration fee.