You must not have had a dad that harped on you about letting your tank get below 50%. If I let mine get down to 10%, my dad would have taken my keys away. There are many reasons people give for this that do not involve zombies and go bags

I remember the garage owner telling my parents they should only half fill the tank to reduce the weight being driven around.

Your car is rear-wheel-drive and the extra weight you are carrying around in the fuel tank helps your acceleration in the snow?

Driving with a near empty tank is more likely to cause corrosion.

this isn't technically correct. the low levels are not causing the corrosion. it's the contaminants that float in the fuel is the issue. when the tank has plenty of fuel, those floaters are not near the fuel pump. as the levels lower, the contaminants become more concentrated and are more likely to interact with the pump. at least, that's how it was described to me. by described, of course i mean harped on at every opportunity the parental unit could berate about lack of proper care for the car blah blah blah

Water (usually what corrodes fuel tanks) sinks to the bottom when it separates. Plus running any other contaminants through your fuel pump is exactly what you want - burn them up and get rid of them, don't leave them floating in your tank until you get a hole in your tank from them.

no, i had a small truck, so we'd just throw extra ballast in the back to help with that

It's pretty much completely pointless to worry about when you fill up your tank. Just fill it up when you need or want to.

nonsense like that gets you sent to your room without dinner.

With EVs I have the opposite habit, I try to recharge at 5-10% on road trips because it recharges faster. (At least with Teslas, I would not want to do a road trip with anything else.)