Possible solution to weak towers
Make anything that is damaged by a tower take 25% more damage from all other targets. This does 2 things. It makes farming under tower easier in the early game for champions who don't have high base ad or spammable abilities and makes diving more difficult. It doesn't affect anything if a tower is left absent though because the tower's damage, health, and resistances remain the same. Dives will still be viable with multiple people because only the person being shot takes increased damage and they can position themselves to take aggro while not being able to be targeted by enemy champions.