iOS 16 still supports the iPad as being a home hub. My parents' iPad is on the latest version of iOS 16 and it works just fine as a hub.
It's only the new architecture that does not support iPads. So long as you don't upgrade to the new architecture, you can still use an iPad. (Users that only have an iPad and no HomePod or Apple TV shouldn't even get prompted to upgrade the architecture.)
Set up a home hub to control your smart home accessories while you're away from home, share control of your accessories with others, and automate your accessories to do what you want, when you want.
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