Don't use Amazon/Google/other service then. Make it work locally in your intranet. (And optionally reach your intranet with Wireguard VPN if it is desired.)
A lot of smart home devices support ZigBee standard and with a device like ConBee (ZigBee USB adapter) you can get rid of the reliance on external services. Run your own gateway that can talk with a lot more different devices and run it in the middle of nowhere, if necessary.
You can also run your own voice command recognition software if you also want to have some voice control for all of the devices.
A lot of smart home devices support ZigBee standard and with a device like ConBee (ZigBee USB adapter) you can get rid of the reliance on external services. Run your own gateway that can talk with a lot more different devices and run it in the middle of nowhere, if necessary.
You can also run your own voice command recognition software if you also want to have some voice control for all of the devices.