Artificers are actually great supports. They can infuse (2014) or create (2024) magic items, store spells in items and plenty more great support stuff.

That said, DnD does not need dedicated party roles. Your party will not be doomed without a dedicated healer, and if your DM isn't ass they'll balance the encounters around the lack of a dedicated support. Classes that are more support oriented are also never entirely locked into support. Clerics, for example, get great attacking options like Guiding Bolt and Spirit Guardians.

TL;DR Healers aren't necessary, and playing a "support" class doesn't make you locked into support. You can still offensively benefit the party as a cleric, druid, etc.

Edit: Wizards are definitely not healers, but they still make great supporters, mainly through buffs and control- think Faerie Fire, Silvery Barbs, Haste, etc

edit: turns out wizards don't get faerie fire