They have had internal support for voice-controlling your music since iOS 1. They had a cross-application API that let you voice control arbitrary music apps on Mac OS since at least 10.4, probably earlier. Music has been a core feature of the iPhone since they day it launched.
It isn't an accident that they've failed to extend voice support to third parties after ten years. If they did plan to add it any time soon, they would have easily been able to get that to market before HomePod. They decided they'd rather continue trying to shove users into their subpar Music service, instead of supporting what users actually want and use.
Conclusion: Don't Buy unless the only audio service you ever use is Apple Music.
It isn't an accident that they've failed to extend voice support to third parties after ten years. If they did plan to add it any time soon, they would have easily been able to get that to market before HomePod. They decided they'd rather continue trying to shove users into their subpar Music service, instead of supporting what users actually want and use.
Conclusion: Don't Buy unless the only audio service you ever use is Apple Music.