Typically Base AD doesn't affect skills because for the longest time you couldn't get Base AD from items, only Bonus AD.
Now that you can access Base AD from items, it skews its usefullness really hard towards champions that have total AD ratios. There's a lot of champions who would love to build Sterak's Gage but since its AD doesn't benefit abilities they're less inclined to
Darius's Q and W scale with total AD, so he still gets ability damage for building Sterak's, Olaf has a total AD ratio on E, Mordekaiser has total AD ratios on his abilities, etc
I think you should tweak certain skills to scale with total AD instead of bonus AD but reduce the base damage for obvious reasons:
Examples of what I mean:
Changing Jax Leap Strike damage from 70/110/150/190/230 + 1.0 bonus AD to 20/45/70/95/120 + 1.0 Total AD
Changing Aatrox Q damage from 70/115/160/205/250 + .6 Bonus AD to 30/70/110/150/190 + .6 Total AD
Base damage ends up being roughly the same but now it makes it so Sterak's AD benefits the skill.
I don't think EVERY champ should have their ratios changed, but bruisers who rely on building tanky/damage probably should