Lol dude
Fighter jets have fbw because they are designed unstable (RSS) it can't be stabilised with manual inputs do u even know what a unstable design is.
The first aircraft to use fbw was a commercial airliner indeed.
Any aircraft which has fbw doesn't mean it's a fighter jet and can pull 9gs
It is because it is a big air craft computer controls make it fly stable and better and also fbw is lighter in comparison to only hydro mechanical controls.
And u can also save some space for fuel etc etc.
A unstable designed can't be controlled w/o computer intervention.
Source-
View attachment 9110
Even small kids know this little things Biradhar
Just a simple question how can u keep stable a unstable design without constant intervention. Which computer does in fbw.
And who said fbw has only applications in military jets ??