Think you have virtually answered your own question. I have tread rubbers but would not go for them again.
1. When washing the car, they tend to trap pools of water
2, I know of several people who have suffered corrosion bubbling up under the rubbers due to rusting fixing bolts.
3. They trap polish residue
4. People seem to think it’s ok to plonk their foot on them to take pics when your back is turned.
I agree. I opted not to have them on my current Morgan for these reasons.
Reason to have them - they protect the running boards from damage from erant kids that jump on them , yes they will do this and damage the paint , the rubber stops this .
Quite the opposite IMHO. Tread rubbers give the impression they are for standing on!
