Are AI agent platforms actually useful, or is this just another cloud bundle?

I’ve been looking at more AI agent platforms lately, and I’m still not sure how I feel about them. A lot of them are trying to solve the same problem: you build an agent, then you need somewhere to host it, connect models, manage keys, keep it isolated, maybe give it a public URL, maybe even list it in a marketplace. I wonder how many teams are actually at the stage where this is the main bottleneck. You can usually hack something together in small demos. But once you want to put an agent in front of real users or enterprise customers, things get messy pretty fast. Model access, compute, permissions, logging, security, deployment, billing. It stops being a “cool agent” problem and becomes an infrastructure problem. I guess my question is: do people here think agent platforms will become a real thing? Like, will developers actually publish agents to marketplaces? Will companies buy pre-built agents and deploy them with one click? Or will most teams just keep building this inside AWS/GCP/Azure because that’s where everything already lives? Curious if anyone here has tried deploying agents beyond a demo. What was the painful part?