You stayed too long...

4 years at the academy and 10 year commitment after wings, plus a few months. I consider myself lucky for not having to extend beyond my UPT commitment. Some of my buds weren't so lucky.

I failed to check the commitment add-on when I took $500 in tuition assistance for my MBA program, cost me 6 extra months active duty. Expensive mistake.

When talking UPT and fighters vs. heavies keep in mind not all pilots in UPT will qualify for fighters. Back in 1982 it was maybe a little over half the class. No idea what it is today. And if going thru UPT with a Guard/Reserve Fighter unit, and the UPT instructors decide you're not fighter qualified then you have to scramble to find a heavy unit that'll take you. Otherwise you get the boot from UPT. Again, my info is pretty old so this may have changed, I'm sure others here can provide updated info.

Before my time, when everyone flew T-37 & T-38s, not everyone was FAR’d (fighter, attack, recon) and you had to be to fly single seat/fighters. FAIPs also had to be FAR’d. With the current curriculum, aka dual track, “FAR” qualification is determined at the end of T-6s. Assuming you are qualified to move onto the T-38 track, aka fighter/bomber track, you have to make another round of cuts in order to fly fighters. Some of my classmates ended up in B-52s and there’s nothing wrong with flying BUFFs but I can tell you that none of them were jumping for joy during assignment night.
As for guard/reserve fighter bound students, they have to finish in the top 50% in the T-6 phase in order to continue onto T-38s, at least that was the case during my time. In T-38s, they have to make the cut to fly fighters or they’ll wash you out. It was rare to see them wash out during the T-38 phase but it does happen. Attrition rates decrease as you progress through the different phases but as the saying goes, it’s not over until the fat lady sings. A few will washout of IFF, RTU, and even weapons school along the way.