I don’t own any Amazon Echo products, but I do own three HomePods — two full size and one mini. Beyond the initial purchase of the speaker, it hasn’t resulted in any revenue for Apple. I use Pandora as it’s default music service, AirPlay audio to it from Pocket Casts and Prism, and use it for timers in the kitchen.
Amazon, Apple, Google, and other smart speaker makers should be pricing them with the idea in mind that they will never derive another dime of revenue from purchasers. Because, anecdotally, that’s what I see from myself and everyone else I know that owns them.