It’s completely a non issue. Beacons are 10%-13% of healing in raid, they are not carrying the healing. They very quickly cap out in value and transition to what would be over-healing if it just didn’t stop transferring any heals. Most of the time you are not getting a full 10-20% amp on healing as your beacon will get filled up quick. They are not smart heals and do not transfer to targets that need healing. Spenders are 10%-15% of healing. Judgement and its interactions is carrying ~14% of healing, Holy Bulwark alone is another 10%, the new ring is between 7%-13% of healing, Avenging Crusader is another 10% these are largely effectively smart heals and don’t contribute to over-healing as much as Beacon would if it could. Which is to say nothing of the horde of 1%-3% healing contributions.
Spenders are weak not because of Beacons but because we have too many sources of non-spender healing.