A lot is possible, even building a helicopter ;) While simple pitch control is certainly easier than the phase-dependent pitch control required for a helicopte

A lot is possible, even building a helicopter ;) While simple pitch control is certainly easier than the phase-dependent pitch control required for a helicopter, a pitch-controlled multicopter would lose a lot of the mechanics simplicity that made multicopters interesting in the first place. But autorotation control code for a pitch-multicopter would be an interesting challenge, maybe for the hobbyist who wants to dive deep doing more than just reimplementing stuff that already exists.