I also do a lot of software system to system and in the long run I feel like ai will solve this.
In principle, MCP servers can be created for just about any OAuth-protected API. However, you still need to create the server, and this is where the usage I'm talking about shines: when working on the MCP server, an LLM can be quite helpful in getting the right APIs integrated.
The same goes for other development that doesn't need an LLM context built-in. If I wanted to sync two calendars, for instance, I wouldn't build an MCP that speaks CalDav and Exchange and then let it loose (though this so-called agentic workflow is becoming more popular); I'd want to build software with an LLM's help that can speak both protocols by having it generate code to handle whatever OAuth tokens and scopes are necessary and then help me deploy the thing.