Immense Amount of Shields on ADCs/In General

What if Grievous Wounds also cut the amount of shields received? The Grievous Wounds on Thornmail, for example, is really meant to try to handle the ridiculous lifesteal of ADCs... not that it actually does the job very well in my opinion, but that's an entirely different conversation.

But, ADCs being constantly shielded and re-shielded by etc. along with kind of seem to circumvent what is meant to be a counter to ADCs, particularly in the late game... that being preventing them from out-healing incoming damage with lifesteal.

So, just a thought, but maybe allow the mechanic that is supposed to counter crazy lifesteal in the late game actually be worth something, because currently any shielding support just drops a shield on the "marksman" and the Grievous Wounds stops mattering...