How to fix support!

Quest items!

You can have items that say for soraka a healer type support you have an item locked to the support role you buy at the start like hunters machete, then you have it so heals get like .5 percent stronger per heal on an ally below 50 percent health.

Or Janna a shielding type support shield an ally below 50 percent health makes all future shields last 1 second longer and become .5 percent stronger.

Harraser type supports could get extra mana regeneration and increased cdr for harrasing. Every time you land any combination of 2 abilities 2 auto attacks or 1 ability and 1 auto attack you gain .2 percent mana reduction and .1 percent cdr

Make a quest for wards on all supports that say when you spot an enemy your team hasn't had vision of for 15 seconds 10 times your wards last 10 percent longer, 20 times your wards see 25 percent farther, 30 times your wards see over terrain, 40 times your wards are now permanent, 50 times you no longer have a ward limit, and 60 times all your wards detect stealth and traps.

Tank supports could get an item quest that says every time an enemy projectile passes through them reduce the damage of all projectiles to subsequent targets that pass through them by .2 percent.

These would allow supports of all types to become far more influential and rewarding to play.