to be fair, support has never had a clear design goal. Traditional supports (which I think are basically enchanters now? not sure but I was basically going to classify them as healers, shielders and enchanters) tended to help by keeping people alive, but had a problem that they were rarely in a good state because any moment could push their sustain power over the top and allow a win, so they were in a tough spot
then we have supporting mages, who give up crowd control and utility for damage and control/zoning capabilities. These were often popular because they could fall back on their mage characteristics if their carry could not be relied upon or was killed
mage supports (like zilean though he's more enchanter, still has a high damage output)
tank supports or support tanks
kill lanes
unclassified supports such as blitzcrank and his instant kill pressure but decent tank ability
support is one of the most varied positions and has little defined objective other than to "help achieve victory, typically by benefitting another team member or the team in some manner but not limited to this"
with the jungle changes, there's talk of the second top-laner strategy coming back
#what has made the game get more than a little out of control, however, is gold income. Support used to be defined by being able to function at less income than other team members. Riot introduced support items to help this and that was fine, now we're getting supports that can have an income EQUAL to their laner or potentially GREATER and that can cause a lot of problems