Support items need nerfs... But so does everything else.

The support items in their current state are a ticking time bomb.

Given enough time, champions that rely on burst like assassins will just be given more damage, creating a power creep. Though support items DO increase support impact, the problem was that damage was too valuable, not that shields and heals were useless, and that damage is more useful even from supports than healing and shielding (just as long as there was some CC, hence the meta where burst mages went bot lane support)

Support's current items are also going in the right direction: they're giving late game scaling by letting supports have more multiplicative scaling with % heals (think ADCs: They have AD, AS, Crit %, Crit damage, AND penetration, along with a level bound % AD increase like lucian's passive, Vayne's Q ranks, etc so their power over time is not as linear), but their actives and other passives are set to be as useful as damage from carries who are already killing each other and tanks a bit too easily.

While it may seem fine, damage before the support itemization was under a completely different context and already suffering from creep, it was balanced with these conditions:

1. Squishy targets have some sort of defense in either mobility, range, or a window of tankiness
2. Tanky targets pressure high damage champions to not blow up squishy targets by making them buy %health or %penetration which is inefficient against non-tanks
3. CC can interrupt damage

Now, shielding + healing is no longer a bit of sustain or a small window of tankiness, it gives squishy champions a lot of extra stats to be closer to tanks while doing nothing to make % health or % penetration any more efficient against them. Eventually damage will be given buffs, leaving tanks to be as squishy as the ADC + support, the unfortunate carry that the support does not shield on time will always die in one hit.

TLDR; lower heal + shield numbers from item actives as well as overall damage in the game as tanks die too quickly, squishy champions will rely completely on the existence of shields and healing and supports will just be walking health bars and stats