Instead of embracing the Java/Kotlin userspace alongside C and C++ on the NDK, with the official APIs, they try to subvert into GNU/Linux.
First of all bionic isn't glibc, secondly the Linux kernel is only a matter of convenience for Google, which they could in theory replace by something else, while keeping the Java/Kotlin and the NDK C/C++ APIs.
Which is exactly termux isn't without issues on modern Android versions, not much different than using cygwin/mingw on Windows.
Instead of embracing the Java/Kotlin userspace alongside C and C++ on the NDK, with the official APIs, they try to subvert into GNU/Linux.
First of all bionic isn't glibc, secondly the Linux kernel is only a matter of convenience for Google, which they could in theory replace by something else, while keeping the Java/Kotlin and the NDK C/C++ APIs.
Which is exactly termux isn't without issues on modern Android versions, not much different than using cygwin/mingw on Windows.