The problem is that you can't host a free LLM based service the way you can host a website, without being exposed to cost spikes the moment it becomes popular (or misused). Lots of smaller apps need a better cost pass-through mechanism; this is even more of a problem for hobbyists/non-profit projects than for commercial ones. We can't keep going with a free trial (costs eaten by developer) + subscription for every little thing.
A better solution is to allow the user to provide their own API key if they want to use it without limits (and really the needed solution is authentication and authorization that provides access to the appropriate API accounts without manually passing around a key). Subscriptions are a tool to generate revenue, not to purely pass on costs.