Suggestion on Enchanter with Shield mechanic

Janna is getting so much nerf due to her shield and protect the adc strat . :C RIot are nerfing her to death where she will be unplayable. Instead of nerfing her that much why not try to make the shield mechanic where if u keep shielding the champ with a certain time limit again like with 30 second , the amount of shield power will be reduce by x% of amount. Thus making janna n other shield champ must learn how and when to shield their target instead of constant spamming shield to their target.

For example if janna keep casting her shield within the time interval of her target her shield power will be reduce by x% and if she do it again then there will be a x% increase of reduce power ( maybe a limit like 1/4 of the shield power if u constant keep shielding the same target)

Maybe this way can help enchanter to learn and effective used their shield thus breaking away from keep shield adc meta