I guess some people are just better at certain games than others.
I have plenty to spare too and we have such a wide range of weapons to choose from, shotgun, colt python, desert eagle, and grenade launcher with its multiple types of rounds. You can save a lot of ammo if you know what weapons to use for what enemies.
I can even complete RE2 in under two hours back then and maybe save like three times.
The only RE that I have significant problem with ammo is the PS2 version of RE4. I specifically mentioned PS2 version of RE4 because that one is much harder than the Gamecube version. Apparently they ramped the difficulty up for the hardcore American crowd.