On the other hand what would be a benefit of investing into getting drivers work with glibc
To run without any translation layers and bionic quirks. That's the main benefit. When the system is using glibc (like Sailfish and Ubuntu do), and drivers aren't, the only way is to translate it like libhybris does. It's a crutch at best and not ideal. It can perform well, but it's still not direct.
But I didn't see any comparative benchmarks published so far. Translation cost might be not critical (i.e. tolerable), but it's still a cost and native approach should be always better.
To run without any translation layers and bionic quirks. That's the main benefit. When the system is using glibc (like Sailfish and Ubuntu do), and drivers aren't, the only way is to translate it like libhybris does. It's a crutch at best and not ideal. It can perform well, but it's still not direct.