I miss it times when i dont hear alarm, but at night last before sleep I ask Allah to wake me for Fajr, I seek refuge with him from shaytin till then and say shahada. It works well and most times I wake just before alarm,Alhamdulillah. Times I miss is when my emaan lower than norm and namaz has been getting a bit of a slog. Missing Fajr always ruins my day.
Apparently waking then going back to sleep without praying Fajr is a sign of being a hypocrite and only being an "outward Muslim", ie only for show. May Allah cause us ti immerse itno Islam and seek his pleasure by praying Fajr namaz, Ameen