What if marksman core items/runes got changes to make their damage ramp

Sorta like how gives a ramp up in damage based on how long you're in combat. That way adc's can be rewarded for doing dps and kiting rather than attacking in one spot while their support saves them and they nuke everything before they can be reached.

The entire point of the class is SUSTAINED damage, they should start off slightly weak but ramp up into a consistent damage point to where they aren't completing shredding tanks into being pointless but at the same time not being weak enough to be run over cause of no damage.

Maybe remove lethal garbage or change it to be a ranged variant of conqueror (DO NOT make it true damage, true damage on ranged champions is clearly too hard to balance).

This could also open up new build paths/item creation ideas since Attack speed based marksman want to run a rune like this and build more speed to keep it going whereas nuking marksman like Jhin or MF would want to run more burst damage oriented runes and stick with crit builds.