Why use an AI gateway at all?

Before picking a platform, I think it's worth asking: why even bother with an aggregation layer? For me, the pain point became obvious once I started juggling more than two model providers. Different API keys, different billing cycles, different request formats, and the constant context-switching between docs. If you're building anything that needs to switch between GPT for reasoning, Claude for coding, or a local model for cost-saving, a unified API is no longer a nice-to-have—it's a productivi