Yes, but the 'am' command is just a CLI Java program. At that point, it would be more efficient to just boot a JVM in the binary to avoid the JVM startup cost every time a Intent/Broadcast needs to be sent.

I believe the Termux API relies on a Java/app process that runs in the background to do stuff in response to API calls. Though I guess you get it for free if you already have the API running for other reasons.