Besides Xiaomi, Huawei and Samsung also have similar types of virtual space environments, that they brand as Private Space and Secure Folder, respectively. All 3, of these, Second Space, Private Space and Secure Folder, are based on an Android OS feature for supporting multiple user accounts, but with some customizations so that these virtual spaces are like an anonymous user account, and only the user in the main account can switch to this (and back), besides switching to/from any of the normal user accounts.
NB: this is different from the "multiple accounts" some might associate with Android phones, which is being able to sign in to more than one Google account at the same time. Here, we are talking about Android OS-level accounts.
These virtual space accounts are one category of isolated environment. The other is the app-based isolated environments available from apps like Parallel Space, Dual Space, and dozens of related apps. The main concern about app-based isolated environments is security risks. You would be trusting the developers of such apps, that they are not malicious. Also, you would be trusting that they haven't included vulnerabilities that could be exploited by others even if they themselves do not have malicious intents.