And what do you do if you run low our out and no gas station within your remaining gas range? Carry an extra tank with gas? This is what we do when we drive on roads without gas stations for hundreds of miles or go into the desert. At the same time running out of fuel isn't fatal, at least not right away, but running out of air/breathing gas is much more serious with more immediate potentially catastrophic results.100%, just like you should monitor your fuel gauge when driving your car.
likelihood of losing buddy although rare, does happen.
I NEVER, and mean NEVER, go into the water thinking or beliving or depending on a buddy to save my arse underwater should things go bad. I plan my dives, and teach it too, to be self sufficient and assume that there is no buddy to help me in case of any issue. I dive as if I am diving alone but with a buddy still in most cases.